Hello, I want to get a bike indicator light to attach to my bike. However, I also want to get a bike rack so that I can transport stuff. The bike indicator lights I have seen only attach to the seat post which will be covered whenever I transport a package which for me will be almost always. Are there indicator lights that attach to the bike rack? Also is there some term that I can use to differentiate the bike rack that attaches to your car and the bike rack that attaches to your bike and let's you carry stuff. Thanks.