(2-part post):
As far as the bill for �2185 is concerned, you ought to consider that you're getting off lightly. If you'd have been involved in an accident which led to the other driver being injured so badly that he was unable to work for the rest of his life, you could have received a demand for several million pounds. Without insurance, you would have been required to pay. (In practice, you'd have been made bankrupt and lost all of your money and all of your possessions).
If you believe that the bill is excessive, you should write to the other driver's solicitor and request copies of the invoices the other driver received in respect of repairs to his car. However, you should remember that the other driver is entitled to add his solicitor's bill onto whatever he spent on repairing the car. Many solicitors will charge �10 for reading your letter, �10 for communicating the contents to the other driver, �10 for reading the other driver's response and �50 for drafting a reply to you. Unless you're really sure that you could win a battle in the small claims court, you should consider carefully whether it's wise to increase the other driver's solicitors bill (which you might end up paying).