they are not street legal, trust me it wont ruin your engine because out of your engine comes out fire, and instead this "flamethrowe" thing makes it come out of your exhaust, the only bad things i could think of are: could ruin exhaust, anything around it like paint bumper, etc. and thats all i could think of. and yeah i seen that mustang on pimp my ride, i seen all the episodes a couple of times, so far all of them still turned out shit boxes, only one i am interested is that pontiac tonight on at 9:30 because its an 81, and thats very close to the one i want as a project car a 6.6 liter 79'...