I have 2001 A3 TDI which appears to have developed an oil leak.

I do a LOT of mountain driving and I fear I may have got a bit over-eager with a top up and put it over the 'max' level... could this cause the leak? I also hit a rock that had fallen into the middle of the road the other day. I managed to brake to a point where I only hit it slowly but similarly could this have cracked something that leaves a spot? The overall oil level remains fine so it's clearly a slow leak.

If something has burst because of the excess oil does anyone have any idea how much a repair like that should cost?

Thanks in advance for any help or suggestions!

 

Your problem is a little too vague for me to diagnose. Can you pinpoint a certain area where you are experiencing the leak? You may have to clean the engine area and drive it. You should then be able to find the exact spot the engine is leaking.