My idea takes the shotgun approach. Lots of smallish attacks all over.
30 men total. 3 man teams. Should be a majority of ethnic caucasian men, but several black and hispanic teams as well. Everyone needs to speak excellent American English, and at least one other language, preferably Spanish.
Arangements are made with Cuban/Venezuelan help, and/or Columbian drug trafficers, to bring over some millitary hardware into the US via the Mexican border:
Two AKs for every man. Folding stock models for greater concealment possibilities. 7.62x39mm, as it is too diffuclt to find 5.54x39mm in the US.
Two or three .45 pistols for every man, with a suppresser for each pistol, so they'll need to have threaded barrels. (.45 is subsonic, so no special ammunition will be needed. The teams can resupply at any Walmart)
One scoped and suppressed bolt action rifle per team
Two or three cases of grenades for each team.
A small amount of explosives and detonators for each team. No more than 300 pounds per team.
Radio jamming equipment. There should be some millitary grade, man-portable equipment that can jam cell phone signals, each team will need two. These may be available for purchase within the US, if so then they will be purchased there.
10 anti-air missles. They should be heat seeking.
Each team buys several cars, minimum of three. Good used ones, say Honda Accords or Toyota Camrys, in the South and West some pickups. Cars will be in good working order, insurance and tags will be paid for. All driving laws will be obeyed. They should go to driving school in Germany (or somewhere else where the rules are followed pretty strictly) prior to heading to America.
Teams will be given cash and multiple American Express cards. Pay with cash whenever possible. AmEx cards are to be used in one city only, then destroyed.
Ammunition will be purchased locally. No sense in sneaking it across the border when it's avaialble for sale here. Whenever possible, purchase items from Walmart. :)
Each team will immediately purchase several throw away cell phones. Two or three per purchase, no sense raising any red flags. Get new ones at each city. And get new ones after each attack. Heasets for handsfree usage are to be used whenever possible.
Goals of the teams is to create terror and chaos and panic. The teams will drive around in their assigned areas, carrying out one attack per city/region, then moving on to the next city. Attack and move on, attack and move on. Do not drive and attack in a linear fashion, move about randomly. Change appearance. Beards or mustaches can be trimmed or removed. Wear different clothes and hats. Wear sunglasses whenever circumstances allow. Change cars frequently.
Each team will do as much of the following as possible:
Arson in the southwest, setting forest fires, grass fires, especially around populated and dry areas, ie California and Arizona, Texas, and Colorado. In addition, each team will create incendiary devices from locally produced materials and set fires in office buildings or houses, especialy houses in poorer areas.
Whenever possible, caucasian teams should only kill minorities and shout "Kill the Niggers!" or other racial epitets. This will cause additional confusion and panic, and perhaps spark more violence. Black teams should target caucasians and shout "Death to Honkies!" Remember, the end goal is the destruction of America. Racist materials should be left in cars and in hotel rooms, so that investegators will suspect the wrong people. Spanish speaking and looking teams should shout slogans about La Raza and Azltan, and "Death to Gringos!" Those teams should communicate entirely in Spanish during the attacks.
"Sniping" like the DC snipers. Modify one of their vehicles with a firing port through the trunk. One man drives the car, another is in the trunk shooting. The third man may be driving another car doing secuirty overwatch and/or spotting targets. They will use the bolt action rifle for this. This should be as random as possible in time of attack and in victim, however, whenever possible shoot young women, especially mothers with children. More than one of these attacks are allowed per city, and can be done in conjuntion with the other attacks.
Break in to houses during the day, perhaps disguised at delivery men or utility workers, and kill everyone inside that house. Then leave. Perhaps leave a small bomb behind set to go off at about 6pm, after the husband gets home and the police have arrived.
Throwing of bombs/grenades off of overpasses during rush hour. Should be easy enough to toss a grenade out the window while driving over a congested highway. This would involve multiple cars so that there is a car behind the grenade throwing car to help block the view of it. Ideally, the driver should not throw the grenade, a passenger should. Both cars would have cell phone jammers and would activate them after the grenade is thrown.
Pick one airport per team. Find a spot near the flightline, in a residental neighborhood. On the same day and at roughly the same time, kill the people living there and fire your one missle at an over flying plane from the backyard. Wait till it has either just lifted off, or is about to land so that it's close and relatively easy to hit. Escape.
Small bombs, no larger than a pack of cards, planted in random products and placed back on the shelves. This should be done at any large store, Walmart, Target, Home Depot, Best Buy, Fry's, Sears, Monkey Wards. Bombs are timed to go off after a few hours. Bombs could be placed in the produce section of a grocery store, at the bottom of a pile of apples or potatoes for example. If possible, enter the employee only side of the grocery store and place a bomb in the milk. If confronted there, simply reply that you were looking for the "freshest" milk possible. Or kill the person, it's up to the team's discression.
Small bombs can also be left in trash recepticles at malls, zoos, parks, shopping centers, gas stations, practically anywhere. Disguise the bomb as trash and simply throw it out then drive away. Small bombs could also be placed in mailboxes. Bombs could also be placed in packages and sent from places like the UPS store, does not matter where it's sent to (although abortion clincs are probably a good idea for misdirection purposes), the idea is that it either explodes in the shipper's warehouse or on the truck.
Bombs do not have to be big or deadly to scare the crap out of people.
Likewise, small bombs can be attached to gasoline trucks at truck stops/gas stations. Timed to go off anywhere from 15 minutes to several hours later.
Mall shootings. Each man in a team drives a car to the mall and parks on different sides. They all have keys to each car. (Probably best if the locks/ignition are changed to take the same keys.) Cell phone jammer is in one of the cars and turned on. Each man walks through killing everyone they can, exiting on the other side to get away in one of the other cars, or to fight it out with the police. Grenades should be taken and tossed about into large crowds or into shops as they pass them. Each man should have one timed bomb to set in a store or fountain or something, so that it explodes after they leave. Each car that is used for this should have a timed explosive in the trunk to go off after, say, one hour. If they escape, they either park the car somewhere where it will do damage, or defuse the bomb. If they do not escape, it blows up, perhaps taking more people with it, at the very least sowing more panic and terror.
Other gatherings of people to be attacked/destroyed in the same general format as the mall shootings:
Community pool. During summer break, especially on the hot days, community pools will be full of children frolicing about.
High school sporting events. Large sporting events and political rallies are to be avoided: too much police/security. Events with only one or two entrances/exits are to be prefered as it's easier to kill everyone inside them that way. Basketball and volleyball games are good for shootings, football and baseball might not be, but you could plant bombs on the school busses.
Elementary schools or day care centers.
Bridal shows. Full of young women about to get married, it would devestate the country's morale.
Churches/temples/synagogues. Attack during worship service on Sunday/Saturday morning, or perhaps at a funeral service during the week.
Bar or strip clubs. For this, shout "Death to Breeders!" and have millitant homosexual literature to leave behind.
Boy or Girl Scout meetings. Show up, kill everyone, then leave. Talk about terror!
Walmart, Super Target, or 24 hour grocery store. Attack at 3am, killing as many of the stockboys and customers as possible. Militant Vegan or PETA-type slogans and material could be shouted/left behind during these such attacks. Or anti-free trade materials.
Since it's a movie, the hero is a small border town sheriff, Bob, an ex-Navy SEAL enjoying his retirement by taking care of "his" town and keeping it safe from "those damn Mexicans". The terrorists came in through his area and got into a firefight with some of his deputies, killing them all. The Sheriff manages to capture one of the coyotes who led them in, a spunky young man named Pepe. Since the terrorists killed all the other coyotes (narrowly missing Pepe) once they were in the US (the noise alerted the deputies), and the coyotes were his family, Pepe is glad to help out Bob and hunt down the evil terrorists. There are stupid/ineffective/bureaucratic federal agents and local officials. Car chases. Gunfights. Explosions. Bob comes to appreciate the plight of the illegal immigrant. Pepe is able to use his coyote contacts in the illegal immigrant comunity to track down the terrorists. Love interest, perhaps between Bob and Pepe (this is Hollywood after all). More fighting. Kung Fu. One liners a la "Let off some steam." And more explosions. Bob and Pepe figure out that the attacks, while seeming random, will spell out "Allah Akbar!" in Arabic if you look at the attacks plotted on a US/Mexico/Canadian map (the feds are just using US-only maps). No one believes them, so they head on their own to the next attack where Bob is mortally wounded, and Pepe has to save the US. But will he? Will he?!