I agree with everyone else that your son should drive within the posted speed limits. But obviously, it may be that he is a grown man living on his own. If that's the case, I would let him buy his own radar detector. Because even if he is a grown man, you would still be encouraging his unsafe driving. His safety and that of everyone drivin around him is what's most important, IMHO.
Hens go broody when you don’t want them to… and won’t go broody when you do.
