Been considering Revo as mentioned in previous post.
Would not consider it without telling insurance. In accident where there is a fatality ALL cars are impounded and thoughly checked ie. NO INSURANCE when upgrade found + trouble ahead. Not worth the risk IMO.
Seen many postings where people claim that Audi etc. will not look in ECU and have to send it away to Bosch which is claimed to be too much trouble, don't you believe it - you only have to get caught once!!!!
Looked at insurance and got quotes as high as £1250 (fully comp + protected no claims) with 20% bhp increase. Wouldn't cover with more than 20% bhp (no good for 207bhp revo on my car). This was Admiral and Elephant.
Best was £90 on top of normal premium for +20% bhp and £135 on top of normal for +30% bhp - Tesco Insurance. Very reasonable. My fully comp with them is less than a third of admiral as well. 2001 A3 1.8T sport.
Hope this is useful to you lucky people with chipped S3's
Pays to shop around guys.