Wobble through the wheel at speed will either be wheel balancing or worn bushes somewhere.
I have managed to lose two headlamp washer covers somehow. I've concluded that they're quite fragile and the first time it probably got knocked loose when the car was being recovered and the second time, on my driveway, was probably when a cat was climbing on it or something.
Pics of car please Philz0r. ST220s are so rare, whenever I see what looks like one, I look at the rear and then think "oh, diesel, pah". Saw a lovely dark blue estate with red leather yesterday though.