One gun I've carried off and on in my car is an AR pistol. This particular one has an 11.5" bbl and a carbine buffer tube. I can shoot it from the shoulder quite easily and it makes a pretty good pseudo SBR as I can easily hit targets out past 100 yards. Best thing is I can carry it on my concealed pistol permit. SBRs are not allowed in my state. It is carried in a tennis racket case and never gets a second look.
Revolutionary War Veterans Association presents Project Appleseed-Marksmanship and History www.appleseedinfo.org