Hah, just read it, so veeeery familiar!! I had a Porsche Cayman S that turned out had scored bores so ...... back to dealer (non-Porsche) ................ major protracted saga worse than yours ............ I ended up having to foot half the repair bill or face a long court case (Sale of Goods blah, blah). So, learning from all that, IF I do go Lexus it will be from Lexus themselves. Have got my eye on this:
http://www.snowsgroup.co.uk/lexus/used-cars/4578588-lexus-is-250-se-l/
Glad yours is now sorted. No problems with it I take it?