I like to run a cable out to the driveway and park a nasty ol' V8 Cadillac there that has the gas drained from it. I take an Ipod headphone speaker and dangle it down into the empty gas tank with my lil' acid bass barking away through it. Now I've at the back of the car, I've rammed a mic into the exhaust pipe and fed that signal back down to the studio where it is recording back to cassette tape. In the car I start pressing on the gas pedal to open up the carboratuer valve and let the sound feed through the entire internal pathway. By the time it finally reaches the exhaust pipe, it is pissed off and a whole lot bigger than it was when it entered that fossil fuel funhouse.
*note - make sure you empty the tank. The first time I did this in the garage with the car running, the mic plugged up the tailpipe and I nearly died from Co2 poisoning as I jammed out on the gas pedal pretending I was working the resonance knob in Hardfloor's Acperience for an hour!