John,
This topic is of interest to me as we will be looking seriously at MH's after our boat sells. I just checked the 2012 Guide to Dinghy Towing provided in the March Motorhome Magazine and it does not reference VW, ANY VW, that may or may not be towable. The TDI would be a great option if it was flat towable, but one would have to check with VW. Check with several dealers as you may get differing opinions, as I did when checking on Subarus. The Guide indicated Subaru as being towable with manual transmission, but my dealer, and others, say not so. Be careful when choosing a vehicle for a toad. Verify, verify, verify.