1. EZ-pass for toll booths. No question a necessity if you go through tolls regularly, and mine has a big M so it pays the bike price (don't use it with a cage! They're free so get the right one for every vehicle).
2. Pile of bungee cords, I've used them too many times already to hold pieces of the bike on the way home from errors.
3. Trunk, have my helmet & jacket in there. Hoping to avoid the gamut of "hey, you rode your bike today" comments. Still expect the questions like "Hey, did you ride your bike today?" because they ask even during a blizzard or whatever.