Hello all.... I need a little technical advice from you very knowledgeable people: I have recently been reading up on replacing the Haldex Quattro controller in my A3 2.0T Quattro S-line. For those of you who don't know (as i understand it - correct me if i'm wrong!!)... A3's, TT's and Golf R32's/4motions use the Haldex form of Quattro. This system feeds most of the power (70-80%) to the front wheels (basically to save power/fuel at low speed and when cruising). When the rear wheels begin to slip under cornering or acceleration the Haldex system throws more power to the back wheels. This is different to the A4, A5, A6, A8 (and R8?) which employ the Torsen Quattro system. This is a much more pure form of 4WD and has an even distribution of power to front and back wheels at all times. SO.... I understand that by simply changing the Haldex unit which comes in an A3 as stock, you can dramatically improve the 4WD performance of the car and make it handle like a 'proper' quattro. The improved Haldex system puts more drive to the rear at all times and throws additional power to the rear much more readily. My question is...where's the best place to get an upgraded Haldex unit for an 8P A3? Am i right in saying they're approx £550 - £600 + fitting? As you are only replacing the existing Haldex part for a new one, will it affect the warranty on the car?? Has anyone already done this modification? Are there any potential pit falls i need to watch out for? Obviously tyre wear and fuel economy will suffer but the handling of the car should be superb compared to the stock 4WD setup. Any feedback would be most appreciated! Thanks in advance guys. Paul.