I've noticed that the tyres on the front of the range rover are rubbing on the plastic arch liner just infront of the airbag. I believe the tyres are the stock size on a 16" rim, both sides are doing it. Is there any reason for it?
If they are indeed stock size and rubbing your liners may have dropped. They are only held in with plastic rivits. However the chances of several rivits coming loose and the liner not being noticeably out of place is very slim. Double check your tyre size.
It's probably cheaper just to find one on ebay in your area. They're always selling rims with a half tread tire on there. I got a whole set of 5 for $100 once, with 90% new tires. A second time I got a set of 5 with 99% tires for $220.