slimGTI09 said:
if on the 1.8T the BOV is mounted upstream or ahead of the MAF then you wont have any problem, but like dragon said on the 2.0T its after the MAF so the engine has imporoper air/fuel mixture so you'll run rich and you'll have the CEL on
You've got about half of it for the 2.0T. I've written waaay too much on the subject to say it again so I'll leave that one to the search tab.
With the 1.8T I have heard that the VAG does not log/control when the DV actuates as is the case of the 2.0T. If this is the case you may not have any "soft" CEL's like we get in the MKV. I had an HKS SSQV on for a few months, I pulled it as soon as the elec. Forge came out.
You will however still run rich like DRAGON and SLIM mentioned. Rich is better than lean for the motor but will cause a bunch of crap build-up' and you won't be at optimum tune.
As far as a DIY or where to get the mount and/or hardware for the install...no idea, talk to your speed shop and I'm sure they will have a few ideas.
IMO, I agree with GTFly....too much hassle for too little sound, stick with stock until you blow it or have a reason to upgrade (i.e. big turbo).