If I was the arty type, I would say to make more of them, give them a clear coat and enter them into a major art exhibition. You will become rich and famous and I can be your manager !
Does depend what parts you're talking about. "Floor pan" is pretty generic - they've got all sorts of add on bracing and inserts that are various thicknesses. The inner sills are really thin (0.9ish) so you may find you need a collection of different pieces. Now you have a welder they will always come in handy!
id suggest you get some thicker stuff to practice on , say 3mm ish or so and when you get the hang of welding on that and using the controls on the machine try your luck on thin stuff