Sorry, no idea for roadster. As I have a coupe it's doing fine on the rear window above the brake light. But after 2 or 3 washes one end started to peel off. It's 1-2mm of the upper right end of the X. I'll try to cut it off to prevent progression. If it gets worse I might order a new decal because I like the sign very much and don't want to miss it.

MI Roadster, sorry for not being a help. I looked at your back (of the car ;-) in the gallery and didn't find an appropriate place to put the decal. On the bumper it would destruct the beautiful clear appearance.

Greets