It depends, if that person that is wasted is still in the "WASTED!" screen and you push them into the fix, THEN that person will get revived and still play in the game normally as if he/she normally would.
But if that person did disconnect after getting wasted and/or watching game the car wouldn't be in control anymore and would simply just a corpse with no lag, so sometimes if you were to hit it other people wouldn't see that, and if you were to push the car into a fix it WOULD indeed get fixed, but the person wouldn't be driving it, no one would and maybe even on other peoples screens the car wouldn't of even been fixed so it would only appear on the players screen that pushed it in there.
Mainly if this would happen, the game would not finish because you cannot damage a car that no one is driving therefore it would simply stay as a corpse, just not on fire and wasted.