You cannot cancel a bid you have made. The seller has the choice of refusing your bid, but this is entirely at the discretion of the seller.
Every bid is binding. If your offer is accepted and the vehicle is sold to you, you cannot cancel your bid or the purchase. The payment must be made.
If you refuse to pay? You will be breaking a legal contract. Aside from the obvious legal ramifications, you will be blocked from bidding.
For a full explanation of our policy with regards to cancellations please read our Terms and Conditions, especially the section about ‘Blocking and cancellations’.