We haven't really missed the car yet, though Tracy and Kira might wish they had it tomorrow--because Kira has a hair appointment in Somerville. I think they're planning to take the T (2 trains and a bus).
I rode my bike downtown this afternoon (it actually stopped raining!) to the Registry of Motor Vehicles to turn in the license plates on our car. I brought the plates, all the copies of the title and bill of sale, and a book, since when I left, the web site said waits were running up to half an hour.
I know people like to pick on the RMV for poor service, but I've always had good experiences there (this is the Boston branch). The greeter knew right where to send me. I only got to sit for about ten second before they called my number. The woman at the counter took my plates and didn't need the other paperwork. She quickly printed out the receipt, with multiple copies for our insurance company and to get a rebate on our excise tax, and she also gave me a rebate form for the registration fee that we'd recently paid. It took about 60 seconds. Kudos to them!
Getting downtown by bike is definitely the fastest option. Driving a car would have taken longer and cost too much to park. It's pretty far to walk. And the RMV is totally accessible by T, but it would have cost me almost $5 and been a lot slower.