Posted 03 July 2013 - 09:24 PM
I guess you'll have to use a trainer like Dollarhide mentioned.
But I feel it's worth mentioning a way of making your car invincible without having to use cheats. You can achieve that by going on a date with one of your gf's (has to be a gf, not one of your regular friends like Roman or Brucie) and then simply fire your gun out your car window. It'll end the date, but for some reason your car will be immune to gunfire and explosions.
Only your car will be invincible though, enemies can still damage your character by firing through your window. But it makes dropping grenades out of your car less dangerous since the car is both immune and will protect you from the explosion.