Two part are the only ones I am aware of that will resist harsh chemicals such as gas or brake fluid. The rattle can 2K is your best option if your not a painter per se. If your using a small spray gun and compressor system then the Urethane two stage products are cheaper to purchase in a liter size with matching hardener, than buying the 2K cans.
If your only shooting clear or even paint for that matter on a rare occasion then stick with the rattle can products.
Oh and be sure to wear correct PPE when shooting the 2K stuff if in an enclosed area, as the isocyanates in the products are deadly on your lungs.
