no visible damage but could there be hidden damage?

[omodos]

Hello to all, and sorry for vague question, was doing about 75-80mph on the motorway yesterday and I basically sudden heard and felt a thud and the X5 jump up as if I had gone into and out of a large pothole or over a massive rock....the car shuddered but never changed direction (luckily as there were cars to one side and the metal barrier on the other)

I couldnt stop as cars flying were behind me.....but further down saw a moped rider on the motorway! going very very slowly and gingerly and looking back, and I pretty sure he must have dropped whatever I had run over.

I checked the car at the petrol station and no visible sign of damage on the passenger side which is the side I ran over what ever I ran over, the wheel wasnt puffed up in any location, alloy not cracked and bushes and tie rods seemed fine ....Any ideas what the best course of action is? do I go for an alignment check etc or wait and see if my tires start to wear unevenly in which case I know I have an issue and damage was caused?

Only time I had a similar thing happen was when I went over road kill late at nite driving a 1973 merc, whole wheel arch was covered in mince meat....and didnt much care for the car....this time I am certain it was the moped buys 'baggage' or something.....

PS I have the stock 17" alloys and tires on it have a decent tirewall height so hoping I will be ok......appreaciate any replies