Shopping for a used car, the terms Non VAT qualifying and Gross VAT qualifying will sooner or later show up. These terms are important for company cars; buying a car privately, it is of no importance.
The tyres of a car are in plain view and therefore easy to check. In order to find out if the tyres are still in good shape, you need to check each tyre individually. Start by measuring the depth of the tread, this will give you good idea of the lifespan. Because a tyre needs a minimum of 1/16th of an inch (or 1.6 mm) tread depth for MOT approval.
When you buy a car, it is nice to have a clean interior, without spots in the upholstery and broken parts. However, these defects are easily solved with a little soap and water and some small repairs. It will become more of a problem, if the upholstery is ripped.
The quality of a gearbox depends highly on the previous owner(s). This means that you can find out what the general condition of a car is by just checking the gearbox. A poorly functioning gearbox can very well mean that the car in general has been treated badly. An important part which you should check in combination with the gearbox is the clutch.