Do yourself a favour and get a used S3/6R ic off ebay.
I've been running a 6R ic for years now and the cooling efficiency of them is superb. Never any more than 10 deg above atmosphere under full throttle conditions. MK5s don't need anything more than that except when doing big turbo conversions, or running a K04 flat out.
A lot of the really cheap ics I've seen on ebay are bloody awful. I bet at least 30% of them have pin hole leaks around the poor welding.
The benefit of OEM is they are designed to be the best compromise for lag, fitment quality, life span and temp reduction. The core quality and end tank shape are far superior to anything this side of APR, Wagner, Airtec, Integrated Engineering etc. These are important features to get right to ensure the air travels through the whole core, not just 40% of it.
All cheap ebay ics do is copy the physical dimensions. Everything else is secondary.