how do I mount a bike rack on top of the trailer lid?

[nwoods]

I'm not sure the best way to mount a bike rack system capable of mounting 4 bikes, on top of the smooth surfaced clamshell lid of my off road trailer.

Suggestions?

Here are images:

 

[Antelope]

Nwoods,
Thule sells tracks TB60 that you can drill in the top, then add a tracker foot and then a standard thule bar. Once you have that you can add your four bike trays. Here's a pic http://media.rei.com/media/686210Lrg.jpg

I can't tell if you have a receiver hitch on the back, but if you do you could go that way as well and will probably be a good savings.

Good Luck