Hi Baz, thanks for your input, I phoned Lexus yesterday and they stated that for my year/model 2015 the upgrades ceased in 2019.
So I guess that is a bit better than the existing 2014. The quote was $420 installed, so I might have to bite the bullet and go with that.
The knock off company does not impress me as they sound very dodgy. Cheers and thanks again. Cee.