I wanted to clarify the excise tax in MA when it comes to vehicles.
Yes, it is assessed every year, and if you have a leased vehicle, BMW FS pays it and you'll see it reflected in your lease statement. Now, this assessment is based on the value of your vehicle by roughly X dollars per thousand. As your vehicle depreciates in value, so does the excise tax you owe. It actually drops pretty significantly after the first couple years of ownership. My fiance I believe pays less than $100/year for her 2004 CRV.
I remember when I moved to Taxachussets over 10 years ago from NY, and they started sending me a bill for the excise tax (I think it was for about $50. I had a 94 Probe GT at that time). Coming from NY, I had no idea what excise tax was, and just thought it was junk mail!
After awhile, I received an official letter in the mail that they were going to take out a warrant to collect my excise tax!
Well at that point I realized this was NOT junk mail and promptly paid my 50 bucks.