Base coat/clear coat?
 

Is there a system out there for model painting that uses base coat/clear coat? Or what is the best way to get maximum shine? Basically I want to wet sand the base and put clear on top for a good shine, should I just use automotive base/clear for this? Or is there something out there?

check the clear coat for aluminum wheels for Car. dupicolor makes it and they are not the fastest for drying, enamel but coating is stronger as well if you looking for durability too.

regular clear are probably not durable . I used these on my Mountain Bike (cycling) fork when I rebuilt my fork with new paint

Check your local hobby shop or Hobby Lobby for Model Master's Custom Lacquer system. These are lacquer paints made specifically for polystyrene plastic but can be used on Lexan bodies too. I'd start with the primer and work my way up if I were you. They have a decent selection of older muscle car era paints as well a few of the nicer late model colors. These are the paints I used to my E-Pede that I posted a pic and vids of on the Pickuptrucks.com off topic thread I started about two weeks ago.

Go to your local automotive paint seller. They should be able to mix most any color for you and put it into a rattle can for base coat. Then ask for the SprayMax clear in a rattle can, it is a 2 part clear the spray out as nice from its rattle can as my 900.00 Geo Paint gun. I was blown away at the quality. Here is a boat I painted and cleared with this stuff

http://rpphobby.com/davatte1.jpg
http://rpphobby.com/davatte3.jpg