Keep it. You're so far under water now (50k ish) and you will forever regret selling if you do. Drive and enjoy it, oh and update to a new deck and lose the tape deck
I know for me, I've had mine 9 years now and don't even want to calculate time or money invested. It's been long paid for and at this point something I'll keep forever. I've sold other cars in the past that I liked alot and have forever regretted it.