I agree with Jim that brass rod would be easier to work than styrene. If the OP isn't a confident solderer(not sure if that's a word, but I'm rolling), 5-minute epoxy applied with small disposable brushes works well too. I used that method on my '56 Beetle's roof rack:

Under the in-progress rack is a small strip of wax paper - epoxy will not stick to wax paper, so there's no fear of gluing your project to the bench if you lay down a sheet on your work surface first.
If brass tubing is deemed more realistic than brass rod, I'd recommend inserting the corresponding-size brass rod into it to prevent kinks when bending it and 'fish-mouthing' the ends with a round file and/or Dremel for a more finished appearance.
www.berrienbuggy.com and
www.larrysoffroad.com are a couple of sites I'd recommend for good reference pics of bare frames
Edited by VW Dave, 13 March 2012 - 03:23 AM.