I'm not the first to do this little mod by any means - but being very sceptical of any benefits I decided to test the outcome and measure the results and I was very pleasantly surprised. The following are all intake temperatures using Vagcom block 4: Without the Gold Tape: Idling temperature: 29 degrees Average temp under heavy throttle: 18 degrees Lowest temp recorded: 17 degrees Then I fitted the gold tape and re-ran the test: Idling temperature: 26 degrees Average temp under heavy throttle: 16 degrees Lowest temp recorded: 14 degrees In the picture above the difference in temperature to the touch between the gold areas (even directly above the exhaust at the back) and the silver, uncovered section in the bottom right is amazing. The gold areas remain only lukewarm even after a hard drive. A brilliant little mod (thanks to JonnyC here). For anybody interested the tape is widely available on eBay - it cost me £55 to do this lot.