small budget 5-speed

[juse]

Is there any cheaper way getting a 5-speed tranny into a Super than the Gene Berg or Porsche-box?
Both of them are far out of my budget, mainly because of their rareness here up north..
Has anyone tried out an Audi or Renault unit as their setup is similar to the rear-engined Beetle? Or would this be too difficult way to get the "missing" 5th gear?

Justin