This is a really nice kit.  The quality cloths, pads and bag add a lot of value to this product.  And, there's quite a bit of wax, polish and oxidation remover included.  So, depending on the surface area of gel coat you need to work on, it should last a while.  I don't know for sure, but I expect the wax would be useable on auto finishes, since it is carnauba wax.  But, you may want to ask Meguiar's before you use it for that - I tried calling their customer service number to ask and gave up on waiting to get through.  Was tempted to knock off a star for that, but I expect most people wouldn't really care about that.  My boat is small, so I might like to use the wax on a car, but I'm not yet sure if it's OK.  In any event, this is a nice kit and your gel coat surfaces should respond well to it.