Freelander TD4 2002 window plug covers

Hi, I have just been to view a 2002 Freelander 2002 3 door with 90k ,I have had a good look around the car and all appears sound, I have checked for the prop shafts being in tact and I don't see any oil around the diff,so all appears ok,it does have a tow pack and appears to have towed a trailer or caravan as their was a spare set of plates in the boot area ,which was dry, all windows work ,not checked if the roof comes of ok as I didn't have time ,all tyres look good as well, my only niggle was the clutch as it did seem to bite pretty early ,I tested with handbrake on and put it in first gear and lifted the clutch slowly ,also their is a black cover, plug on the rear window missing possibly a potential leak ,not sure but it was easily noticeable when viewing, I will go back for a second look as it was raining and I have never purchased a car in the rain ,could anyone tell me what part is that is needed to repair the window glass cover , I may try and factor a new clutch in the price when negotiating as well,also their is tax on the car until Jan 15 and the guy who is a trader but runs from home (I believe) says the tax can go with the car as he purchased before Oct 1st , I am not sure on this as I was lead to believe I was responsible for taxing the car before I put it on the road ...any help or advice would be appreciated .Thanks