Registering Car in VA when you live in MD

Hello. Is it possible to register your car in VA when you live in MD? I called the DMV and they stated it can be done. Im not sure why im so skeptical. Also has anyone heard of the uninsured motorist fee of 500 for a year? Is it possible it can be prorated for a short amount of time? Im so skeptical after calling the DMV. Also how much was your tags and title all together? Did they require you to have a inspection?

Thanks!