If you are following close enough to get those symptoms from a Motorcycle, You are WAY TOO CLOSE to the bike. The machine you are in (or on) has a brake control device. USE IT !
enough allready dude,we get the picture.You dont like H.D. So what. I have 30 inch drag pipes on my 120 cubic inch panhead.Ride behind me for an hour and see if you can still hear!