The past history of a car can reveal a lot about the life it's lead with it's current owners. If they've had the car since new and don't have any old MOTs or receipts for servicing etc, this should raise alarm bells. Do they have something to hide? If not it shows how much they care about their car if they can't be bothered to keep proof of how well they've looked after it.
If the old MOT's are present it's advisable you check for any mileage "discrepancies", it's very easy to roll the miles back on most cars to increase their value. Digital meters are just as prone to being clocked as normal ones.
Some cars that have been involved in accidents will have been resprayed, check each panel for the correct colour match. One of the best ways to check if a car has had a complete respray is to compare the colour in the boot to the colour of the outside. If there is a significant difference, the chances are the car has been involved in an accident and had many of it's panels resprayed.
Insuring a car can be the last of your worries if you've bought something that just isn't practical for your needs, make sure you check out our buying guide to make sure you're getting the car that is right for you.