Thoughts on what to do with unexpected tax return?

Have received a large tax return from the IRS (filed in october). Trying to figure out what to do with it.

Have life/disability taken care of, Roth is maxed, have money in mutual funds and long-term stocks. Only debt is a vehicle I purchased last year at 0% interest. Planned on saving a small portion for honeymoon (wedding has passed and all paid for). The rest is for whatever. Because I didn't expect it, and actually expected to have to pay more, I feel like I'm playing with house money.

Thought about paying off car note, but figure even putting the cash into a money market and gradually paying off car, I'll get out ahead. And I'm one that drives a vehicle a while (also have a 2003 Silverado). I could just go with the capital one 360 money market and get 1%, instead of the abysmal rates from banks. Or I could play the markets, though I have no experience. Or invest in real estate; the threads about buying and renting intrigued me. I've talked to my brother, who is in construction, about flipping houses or becoming landlords, but he's too busy to do anything currently.

One caveat: I'd like the money somewhat available if/when I'm looking to buy/build a house in the next 2-5 years, which means buying and renting may be out.