[tacollins]

(dealing with under body dirt/grime)
I'm guessing they are crusted with dirt or road grime, What I usually do since I don't have a pressure washer is take it to an automatic car wash with a real good under body sprayer. If you do this make sure it's a touch-less wash, I learned my lesson on the ones that beat the car with those brushes or whatever you call 'em when mine came out with a scratch from a piece of gravel or something caught in the brush thing. If you have a pressure washer you could probably use that.

(possibly useful info on my car)
Talking with my dad and the best we can remember the one I have (2004 coupe) has metal fuel line from the filter to the engine and either a metal or braided fuel line from the tank to the filter. I dunno if the older ones had rubber line like is on my cutlass but the lines on my car can't be kinked... you'd need a new fuel line.

(pretty useless info on my car)
Mine used to get 26 mpg, but my lifters are going bad and the local gas is eating my car >.< (the gas is so bad it actually feels like the tranny is going out, heet is awesome in this case) I'm figuring I'm now getting 20 mpg now about 190 for every 9.5 gallons (approx. 3/4 tank)