Only 2 people in my neighborhood have them though they are actually competitors in many different state-to-state, checkpoint-to-checkpoint races.
The 1st neighbor has 3 Gumball 3000 stickers. One on the windsheild, and one below the left and right brake lights on his Porsche 996 Turbo S.
The 2nd neighbor is one who says has not done the Gumball itself for a year or so, but was at the Monaco GP (supercar one) last year.
He has 1 Gumball sticker (small) on his windsheild in the bottom driver's corner so it looks custom made or something.
The other sticker is a Monaco GP one which he made. It rests on the rear windshield at the top of his Ferrari 550 Maranello.
I haven't seen my 550 neighbor for some time now, nor the car, but my 1st neighbor has apparently been working on his son's Cuda.
2007 Acura TL Type-S (AEM V2, R-V6 Race/J-Pipe, ATLP Quad Exhaust)
2011 BMW 328i Coupe