I don't know. I e-mailed them about both questions, but no reply yet. The PC code still works, but I'd be careful using it right now.

Update: A new PC code is on the offers page, offering $5 off the underage fee until July 31. I personally recommend not bothering with the rental, to avoid wasting money on a taxable underage fee. If you spend more than 24 hours on the ground, that taxable fee comes back to bite for a second day. I recommend underage folks go back to doing things the old way, slightly less convenient but infinitely cheaper.