Thanks for all your replies.
So I do indeed have the valet key, According to Lexus Sidcup they told me it is not possible to make a new key/transponder from a valet key and told me £1000+ for new system (ecu). Is Lexus correct?
According to this artical (USA) you can do this from a valet key. http://www.ehow.com/how_7641569_program-key-using-valet-key.html So whay are lexus telling me you cannot make a new transponder from a Valet key.
I want to make a new master key as opposed to the valet key I already have.
2 options:
1, I contacted a locksmith and he quoted me £300 for the master key and reflash ECU ( not sure if my valet key would work again after he has done this?)
2. Ebay a transponder key from the USA http://www.ebay.co.uk/itm/Lexus-4C-transponder-key-/220836548334?pt=Motors_Car_Truck_Parts_Accessories&hash=item336ae24eee £20+ VAT Get the key cut for around £15 and do the programming myself.
My valet key works fine as it stands, just need a backup solution.
Andrew