You bring up a good point about being able to carry an SBR loaded in your car. State laws vary but if the classification has now moved from a pistol to a rifle the ability to carry it in a vehicle loaded may have also changed.Being 45 years in age and given the fact I started shooting in Boy Scouts, I've given money to many pro 2A groups thru the years. Even though my local gun club is NRA affiliated, I helped get the Board to recognize non NRA Memberships. I have not cared about a single pro 2A group after talking with GOA. GOA is not too far behind the NRA when it comes to helping out Clubs. Most of these 2A groups are just a profit center like BLM.
Since I have 7 pistol braces, my first being 10yrs old, I figured why not help the little guy who told the ATF to pound sand. A $200 tax stamp on an SBR is ridiculous, as It can no longer be carried loaded in my vehicle. While I live in Michigan, I would rather push back on
our current Political Hacks than just roll over.
We already know that if they are classified as an SBR they can't be taken across state lines without a permission slip, nor can they be sold without processing a transfer through the ATF.
Since this issue is in such flux right now I would say "caution" is the word of the day.