Jeep's and Harley's
Only if the truck is not Immoble .... he he heLOL. No, by no means the perfect defense. Depending on terrain, put them in buildings. Another option is park them in a trukk. If the trukk pops, your screwed, but when it does, you might get lucky and kereen 10 inches in the opposite direction and then you avoid an assault. Also, the flamer will not be able to hit your guys. Trukk is cheaper than a minimum gretchin squad too.
*walks away chuckling*