Do you give the color any time to dry before putting the clear right on? And why the hell are you putting lacquer thinner in your clear coat?

Maybe you should tell us what kind of materials you are using too. I've never heard of someone using a modern clear with lacquer thinner to actually clear a car.

I've used lacquer thinner in my clear for cut-ins but never just to clear the car.

You should be adding an activator not lacquer thinner.