Bumpers (and West Coast Drive)

[Grim Tuesday]

Our team is looking into building a practice chassis; west coast drive style, based off of the 'universal chassis' by team 221. However, thinking about it, how do teams connect bumpers, as usually required by the manual to this frame? In the past, our team has always essentially clamped them onto out outer frame. However, with a WCD, you simply don't have an outer frame. How do teams who use it get their bumpers on? Do you have a raised superstructure?

Lets make this a more general thread: I've seen lots of interesting ways for teams to get bumpers on and off, and our team has experimented with a couple methods of attachment (our latest was wing nuts). What do other teams use? What works well?

Thanks in advance.