S8 FL Harsh Ride

[ahd91]

So now that the car is working again, I can get on to resolving its other issues.

Recently (I think) the car's ride seems to have become quite harsh, and I'm not sure if this coincided with two new tyres and a tyre rotation that I had a month ago.

Now it does have the 20" alloys, so I'm not expecting to float down the road, but I feel like every bump can be felt, and there's a lot of road noise that comes up into the cabin on most roads that aren't smooth. Sometimes it can jolt over larger dips in the road, though it never feels unstable or loose. I'm running at 40psi all round as suggested by several on here - I'm not sure if lowering this by 4-5psi is a) going to make any difference, b) going to put the alloys at risk.

What should I be looking for/are there any known suspension weak spots?