The brief
The Q2 had a thud over speed humps, a fine shimmy through the steering at motorway speeds, and the front tyres had started to feather on the inside edge.
The owner had already been quoted lower control arms by another workshop. He came in for a second opinion before throwing parts at it, which is exactly the right instinct. All three of those symptoms can come from worn front geometry, but worn front geometry has more than one possible cause: the control arms, the links, or the front subframe bushings. Quoting arms before testing is a guess, and a guess on a suspension job is an expensive way to find out it was something else.
The diagnosis
We pry-tested the lower arms. Both were within tolerance, no significant deflection in the bushes, the ball joints fine. The arms were not the problem.
The clunk was coming from a different place: the front subframe bushings, the big rubber mounts that hold the subframe to the body. They showed visible deflection in both planes when levered, and the rubber was starting to separate from the inner sleeve on one side, which is the failure mode for these. When those bushings go, the whole front assembly can shift slightly under load, which produces exactly the thud, the shimmy and the uneven tyre wear the owner had described.
So the right diagnosis was the bushings, not the components hanging off them. Replacing the arms would have left the actual fault in place.
The work
This is a subframe-down job. Supported the engine, then dropped the front subframe far enough to get at the bush seats.
Pressed out the failed bushings, pressed in fresh VAG-spec replacements to the correct depth, because press depth changes the subframe's position relative to the body, which throws the geometry off if it is wrong. Reinstalled the subframe with new bolts torqued to spec.
Then rolled the car onto the alignment rack for a four-wheel alignment, camber, caster and toe brought back to factory across all four corners.
The outcome
The knock gone. The shimmy gone. Alignment in spec.
The owner avoided paying for control arms that did not need replacing, and the Q2 went home tracking straight under braking and silent over speed humps. For the owner, the practical wins are a front end that feels solid again, tyres that will now wear evenly, and a repair that fixed the actual fault rather than the one that was easiest to guess.
Getting a second opinion before the work, in this case, saved the cost of a whole set of arms that were perfectly fine.