Car is a 2000 Avant 1.8T Had a knock for a while and can't work out where it's coming from. It comes and goes, but seems to be more regular now. It's coming from underneath the front, I think it's the drivers side, wife thinks it's the passenger side, it can be felt through the floor and is easily audible. It knocks only once on acceleration,doesn't have to be from a stand still but the brakes need to have been applied for it to knock again, and the acceleration doesn't have to be fast. All arms have been checked and seem ok, passed the MOT recently while the knock was there. The ARB link bushes are debonding but dont rattle like I'd expect Strangely,during the period of hot weather several weeks ago it wasn't there, it only knocked again after the car had been driven in rain! Other symptoms, not necessarily related is the OSF tyre is wearing on the outside edge, the car pulls slightly to the right if you let go of the steering wheel, I have had the car on a 4 wheel laser alignment and it was adjusted to correct tracking,but it still pulls, it does go in a straight line with the steering wheel straight. Track rod end , OSF upper arm and NS engine mount have been changed recently in the hope of curing the issues without success. Any ideas anyone?