Thankl you all. In the meanwhile, I found out from Lexus service in Greece, that if you replace the NAV DVD player to another one and I quote "NAVIGATION ESU ASSY , serial number 86841-50101" , it would work for sure. They have installed it already on another US imported car and it worked fine. They suggested that I should try to find it on ebay or another site , or in a junk yard (most likely in Germany), because it is too expensive to buy it new. (something around 4.000 Euros). I have already looked for it but no luck yet. Do your research as well and we'll be in touch.
