If you are spraying the car yourself, in your shed/garage then acrylic is the only way to go. Spraying 2pack in a domestic setting is illegal and potentially deadly. You really need a proper spray booth with air fed respirator to ensure you don't breathe the isocyanates in 2pack. You can get away with spraying acrylic in your shed without all the gear, it can make you sick and get you high but usually won't kill you like 2pack will. Even if you have a ventilation system set up to take the fumes out of your shed, you may be still endangering neighbors, children and pets.