I created a tutorial with some info, but since no one actually checks the tutorials and I'd like to avoid hundreds of new threads for this problem and link it here : :link:
If your models supports it you will be able to use big maps llike the Truck or the full EU/America maps on your old TT.
So far it was tested on ONE V4, V8 and XL.
Again: don't blame me if it does not work or you deep fry your TT!