for taking my thread so OT

I think it's just cold weather + rain + hot car = team. In the car wash today, as soon as the jet hoses were put onto the car, I noticed a bit of steam ingress from the air con vents so I'm fairly certain there's no issues.

All fluid levels are fine and I've done about 400 miles since the initial incident (and also tripled the mileage in two months ) so everything looks fine.

Thanks for your help/suggestions everyone

Car Wash!

Glad that your problem has a simple solution!

Hand car wash!! The car was covered in salt (which looks like it's corroding the door handles) so it had to be done and it was waaay too cold to do it myself (lazy, I know )

When washing an Aero it is important to cover the Heater Intake... I use a simple "large plastic shopping bag" split down the middle and laid butterflied across the heater intake.

It fits easily under the centre line of the bonnet and stops water poring in through the bonnet vents!

On earlier cars this also stops the small damp patch behind the radio on the gearbox tunnel after a wash.

Had the same experience in my S3 and it was simply and definitely an air-con issue. I had a similar thing on my 1989 Renault GTA V6 many years ago (still have the car but the air-con is currently out of service.)

In my case I had driven the car about 150 miles (to the factory) using air-con all the way. Parked up and then re-started about 15 minutes later. The car immediately filled up with steam and with windows open and fans on max this cleared in about 5 minutes. Not a leak specifically and not anything other than an air-con quirk as far as I can see. What the longer term prognosis is I have no idea but I doubt it helps with the long-term health of the air-con.

Thanks . The car has to go in for a service soon anyway so I'll get my local dealer to make sure everything's OK, just in case!