what determines expiration date on car registrations?

The car you 'registered' in March was probably just transferred to your name because it expires in May. In May you ned to register it for the year ending next May. There is a number on the windshield that says which month it is supposed to be registered in. It is also written on your registration. They do not register for two months. The car may have not been registered for the previous year or you just got it from someone else.

I was a little surprised when I bought a used Jeep. I bought it around December or so, and the sticker was for April,09 When I went to have it transferred into my name, it had to go through inspection and get a new sticker. BUT, the new sticker was for April,09 as well. I asked why I didn't get a sticker that would be good for a year, and they just said they didn't do it that way.

I don't think there was a separate charge for the inspection, just the transfer fee.

also i dont think that they mail you reminders. in maryland you got a notice in the mail when it was time for that, actually all of the states i lived in did that. here they dont. some of the states you can even do mail in registration

"notice in the mail?"

"mail in registration?"

This is the VI, you amuse me.

The best that I can tell the month stays the same from the cradle to the grave through as many owners as the car has. Basically from the original month that is was registered. I let one of our cars sit for four months while I repaired it. When I got it inspected the month on the windshield stayed the same.
Jay