Why hasn't one seen spy shots of the LC, when it has been suggested at times this will arrive before the next LS? At least in mule form (slapped together RC maybe)? People from Japan have reported that test mules were running around in 2014, but as usual, no photos in the least. There is a reason why one hears more about developments on the European front, than the Asian front. I don't see what they have to honestly hide. Prototypes have to have be out there somewhere of course, even for the LS as well (no renders for that even).
they are referring to TNGA which is in new Prius and said to be 15-25% more efficient overall. Platform for RWD Lexus will be called differently. If Crown will be sharing LS platform, that means that quite likely all RWD Lexus models will be on same basic platform... that means that these cars will have to be significantly lighter than before.
It is very much expected that the LS and Crown will share a RWD platform, but I thought they already did somewhat (N platform). A proposed Century redesign in 2017-18 might also share the same platform, but maybe lose its V12. Your theory makes sense, as using the same name TNGA would tie RWD and FWD too closely together. MB still utilizes MFA and MRA separately, so I should've taken note of that.