re: What to do with end of year bonus

Sounds like you're in great shape. If it were me, I'd scrape together another 10k and pay off the car and the 50k loan. You're already maxing your tax advantaged accounts with extra money to invest.

Think of it this way. If the car was paid off, would you go borrow 20k against it to invest with?

Once you're down to no payments except for mortgage, you'll have the flexibility to do whatever you want with the additional monies. Congrats, you're killing it!