If you are going for an early-Beatles-meets-Nascar vibe, add a harmony vocal on the chorus and you've nailed it!!!
I get your constraints, but I totally get what you are trying to do. I think you could get a different tone on that lead guitar, it sounds very thin and just noodles around, and it sounds kind of like you recorded it with a heavy blanket over the amp. The rhythm guitar sounds much, much better - its very clear and well-mixed.
Maybe drop the lead guitar out of the background while the vocal is doing its thing? Just a thought.
cheers, hope you get some time for it!
-Tom