funny how something so common can be such a head scratcher. but then if you are a commuter you will learn to be 1/2 Marine adapting and overcoming. I'm a fan of rear trunk racks and Planet Bike Superflash, but I also like having a rear reflector too. Just 1 bike doesn't have the reflector. I've made my own custom adapters for each situation using flexible metal strapping from the hardware store. It's easy to cut with a bench vise and hack saw. easy to bend around seat stays and rack supports. It already has holes so you just need to get the right bolt; washer & nut. It's so easy and versatile I've even made adapters for my left drop bars. It's good to have a lite on the rack but it's even better to have a 2nd on your left drop cuz the passing driver has a reminder to stay clear as they pass and are less likely to cut back as soon. it makes a difference!