I think the trouble with selling a 1.2 second hand is that many of the people buying that type of car are doing so not just because they are cheap but because a years insurance can cost them a four figure sum. Therefore having the car modified makes it even more difficult for an 18 year old to afford from the insurance point of view.
On top of that the new models are being given away with free insurance, three years breakdown cover, three years warranty, three years of no MOTs, a years tax and the excitment and pride of getting a new car. That little lot is enticing when you are young and dont earn much.
As a result second hand values are very low for this type of car. I would say the insurance issue makes the car worth little more than an unmodifed example. Therefore best to sell the mods seperately. I hate to say it but if you get £5000 for it be very pleased.
At three years old many people are coming to the end of the selections scheme and are handing the cars back. The cost of keeping the car is a final payment of typically £3500. I am sure many people would rather go up to someone about to return a 3 year old Clio to Renault and say "here is £3.5k, buy the car outright and give it to me cheers".
