So today I took the car out for the first time since getting back. While I was away in Afghanistan my family had the front tyres changed as requested as they where starting to look a bit dodgy tread wise. Everything feels fine and dandy for a little while until I get up to speed on the motorway and then suddenly the steering wheel starts shaking. Not massively, just enough that you notice it and that it doesn't feel right. Then it stops for a while. Then it starts again. Dropping my speed below 60 seems to get rid of it entirely. Thinking this was just a little bit odd I decided to turn back and take a look. Now what I know about cars can be pretty much summed up in the phrase "I can drive one..." but I am fairly sure it's not the suspension. My brother assures me he watched Kwik-Fit balance the tyres and adjust the tracking when he had them changed. I checked the nuts and they are all tight and correct. However upon inspecting the wheels I noticed that the front wheels where missing something as is displayed in these photographs... Rear wheels Front wheels There appears to be some kind of cap or cover missing from both front wheels. I suspect they went missing when the tyres where changed, I didn't notice as there is another cover that goes over the nuts hiding them from view. My question is could this be a cause of the shaking (They are missing from both front wheels) and/or is this dangerous or is it ok to leave them? The car is getting on in years now and won't be with me for very much longer so I don't want to go splashing huge sums on repairing her but I need her working for now so any advice I can get before I go down the route of paying for a mechanic or gobbing off to Kwik-Fit would be appreciated. Many thanks.