l have rang the main fitting company is with no avail

Assuming you are in the UK try GT Towing in Potters Bar.

In a Lexus LS400 shop !

Here;

http://towbarsdirect.co.uk/Lexus.htm

or;

http://towequipe.co.uk/?gclid=CNnnhrOWsJQCFQ5NQwod23wEuA

or;

http://advancedtowing.co.uk/home.html

my friend has a Lexus and was also wanting a tow bar for it, after long extensive search he has given up, and has now decided to part with his beloved Lexus, l do not think he could find a supplier for a tow bar for his vehicle, and l think he was told that the vehicle was not designed for towing

towsure.co.uk