what kind of fenders are you planning to use?

As mentioned here in another thread, with SKS fenders (p35 for example) they have these "Secu-Clips" that normally go on the front fender for safety in case something like a rock or twig gets jammed under the fender, it un-clips. You can get a couple extra and use them on the rear fender as well - that way you can just yank the stays out of the clips quickly with no tools needed, when you need to get the wheel out.