Yesterday I test drove an 09 octy that the speedo/odometer has been replaced after it broke and only shows 413 miles as a result. This was at a main dealer, the car was an ex-lease car. he says it's actually done 15000 more.

The dealer says Skoda will provide a letter explaining the previous miles and they will stamp the correction in the log book. How much should i be worried about this? would the 15000 more be the real extra miles?

If i went for it, what do I need to make sure the dealer provides me with about this?

Id be worried because a main dealer should be able to update the mileage on a new cluster

Yes, when replacing the dash cluster, the dealer should have programmed the correct mileage.

What engine was in the car? With some cars it's possible to see the mileage stored in the engine ECU as well as the dash cluster, so you could verify the mileage given by the dealer and also have the mileage on the cluster corrected to reflect the true mileage.

We can help with that should you require it.

As already stated, the cluster should have been updated (assuming a new cluster was fitted).

Ask to see the log book. It should already show the exact mileage when the cluster was replaced. If not, I would see that as a problem.

if the dealer replaced the dashpod then as part of the process the mileage is copied from one dashpod to the replacement.

Buying a car with a replacement cluster in itself shouldnt be a problem, but if done properly you would never know it had been changed. For example the dashpod on my old octy was changed to a vrs one with maxidot by the dealer in Fareham, and all settings including mileage were transfered to the replacement cluster.

The test, I would suggest, as to whether or not it's okay is to put yourself in the position of the buyer to whom you're going to sell it in the future.

Most people would, or should, run a mile from any car which looks as if it might have been "clocked". Just think about yourself explaining this to some stranger in three years.

I agree with the other posters who say it should be arranged to show the real mileage.