Hi, my daughter has a A3 2.0tdi 109k miles and I just took it for a drive. There are a few strange things going on. Any pointers what to look at to fix.

Vibration at 70mph.. I think this is wheel balance so will get them rebalanced

Engine rattle at c2000rpm, light pressure on accelerator, noticeable in 3rd 4th 5th and 6th gear. Quite loud especially at 70mph on motorway cruising speed.

Speeds and rev counter.. the brightness changes from very bright to very dark.. almost like the light level adjustment is changing itself.

I've had a search but couldn't find much on the forum. All help much appreciated.

Thanks Mark

Vibration could be anything, wheel balance, bearing, brakes. Wheel balance is as good a place to start - relatively inexpensive. Bearings usually have constant drone from 40mph up and really bad ones will have a wobble. Brakes, then sticky caliper will force contact with disc. You can usually smell. Drive for 10-15 minutes and coast to a stop. Brakes may be warm, but definitely not hot. If all that checks out, the only other thing is suspension arms. You'll normally feel a clunk over uneven road surfaces.

If car has auto lights - it may be ambient light sensor. VCDS might mick this up in a scan.