muffler dimensions?!

[koabi at seeohdee.com (Koabi Brooks)]

It's snowy and ~0deg F so instead of laying in the parking lot, I will ask
here:

What size muffler will work well with a mkII with a small spare?  I am
looking at magnaflow options since my brother's friend is a dealer (no not
that kind of dealer), and I will be attempting 3" to let the turbo breathe.
Basically what I am trying to avoid is buying a muffler then taking it to an
exhaust shop only for them to tell me that it won't work.

Oh and has anyone tried dual 2.5" out?  I was thinking 3" in and 2x2.5" out
to try to keep a stock-ish 16v look.

Other VW content: TDI + ice = fun

Wow I'm so bored,
koabi