Take the sticker off straight away and put it on the wall of your garage. Stickers after the event are try hard IMO.
As for the helmet...you could probably take that off unless you are super clumsy and bump into stuff and think you might need it still. Not sure how you go about washing your hair while still wearing it though, maybe you don't, just let it go all feral and dreadlocked. Then go and get some boot polish (a la Sam Newman) and a low cut tennis dress (and an attitude) and you can get a job doing celebrity look-a-like appearances as Venus Williams!
You know, somebody actually complimented me on my driving today. They left a little note on the windscreen. It said, 'Parking Fine.'So that was nice.