My pre-BFM name was FendrBendr ("FenderBender" wouldn't quite fit), and it's a play on my poor racing skills (I always seem to find every single tree in Timberland, every boulder in Danger Canyon) but also I love guitars and have several of them. In the end, "FendrBendr" wouldn't fit with tags, so I shortened it to "Fender" -- voila.
The name says basically that I like puns and wordplay, I enjoy playing music and being creative, but also that I try not to take myself too seriously. Being a guitarist is a big part of my self-identity (i.e., how I define myself to myself), so "Fender" is a good fit. I also am obsessed with sailboats, and I crew on race boats twice a week, but "FenderBenderSailboatRacingGuyArrr!" was waaaay too long for tags.
"Fenders" also happen to be what they call the hull-protecting pads hung over the side of boats when they are docked. So I guess that's a tie-in, too.