I always thought if I told a cop "no you cant search", they would figure out somehow to search because you said NO. What are they going to do when you say no?? just say "ok, no problem, have a great day young man!"? Doubt it. If my stuff was not homebuilt, I wouldn't be so worried. But if I get pulled over and they find a ak-pistol (home built) in my pickup, they are more than likely going to flip!
I did put some markings on it, and a personal serial number so they dont think I defaced the numbers, but there still is no registration. Although we may be aware there is no registration needed on a homebuilt gun, most of them are NOT! And that is what scares me....but I'll still go shooting with it.