For the key codes and immobiliser codes - unless you have the script or way of getting them - don't advertise them... You are currently showing Nissan and other vehicle makes yet when you click they flit back to the same page... Probably just a niggly thing for me, but it annoys me and makes we want to leave your site because "it doesn't work".... if anything putting up something nice, simple and polite directing the user to phone you would be more beneficial than having a site that doesn't work.
What kind of guarantee do you give for the codes that you supply?
What does your insurance cover exactly?
What kind of insurance are you providing to the car owners when a criminal who get hold of a Vin number of a vehicle and arranges for a new key to be cut and immobiliser to be shut down in order to steal the car?