Best Motoring compared the M5 (5 speed manual) and a Mercedes 500E (auto) against the Toyota Aristo V (the older shape one with the non VVT-i 2jz-gte) with an auto on a slightly damp track in 92 (I think the track was Tskuba....not sure) and the Aristo was faster around it than both the BMW (2nd) and Merc (3rd).....
I have a video on my computer (also Best Motoring) racing a new Skyline 350 GT a 350Z (almost the same car really) against the M3 (latest version with the 3.2 six)....i cant remember the exact times but they were all about equal around that track.
The thing with Japanese cars (especially the larger ones that arent sold outside the JDM) is that the press releases/hype doesnt seem to get outside of Japan.....notice all the talk about every new little revision to Ford and Holden products in our motoring magazines?.....no mention of JDM cars (Not suprisingly really as they arent sold new outside Japan)....Japan makes some very fast sports sedans and has done for sometime....just not many people know about them
I hear that Toyota NZ is introducing a large sedan later this year....Im hoping its the Crown series!!! (I doubt we will get the 243KW 3.5 V6 option though