A1
: 
(you may want to read all of this 'cause it's got some important stuff you'll probably need to know!)If this ain't the PS2 version, I can't help ya. But if it is, then go to Eva's garage (hopefully you didn't beat that mission, 'cause you'd have to start the game over, which is a pain in the ass.), accept the mission, and get a RTR car, the tank engine, the fire truck, and the custom wheels from the pirates, and get in the car. Drive the car to the side of Eva's garage, right behind the spot where you drop all the crap off. Then, cancel the contract and say no to retrying it. Climb out of the car, and go to Eva. Accept the mission. The car should be parked, facing the road. Do the mission and this time finish it. (be sure to set a waypoint where the garage is, it helps ya find it quicker.) Go back and the car should still be there. Brind it to the HQ, drive it into the "stockpile vehicle" zone and you have the sickest car in the game! you may want to put in where it shows how freindly the factions are in the pda right, left right, right, left, right, left, left (it'll keep ya from blowin' the car up from too much damage, just don't flip it! if it's on it's side and NOT ON FIRE, rifle bash it on the top of the car 'till the car flips back on it's wheels. If it's on fire, shut the playstation 2 off and turn it back on.) This is how I got my El Diablo in the stockpile. HAVE FUN!
A2
: 
Crap, sorry! I put in the wrong code. The code I MEANT to tell ya to use was up, down, up, down, left, right, left, right. The previous answer was by Aaron Parker (ME).Well, now that you know the right code, you can go take the bad-ass ride for a spin, without worrying about damaging it Just remember what I said to do if the car flips on it's top or side!