I changed from the OEM fitted Bridgestones to Toyo T1-R's on my IS250 (also changed from Bridgestones to Toyo Proxes Four on my IS200 Sport). Even though the Toyos are on 19" rims considerably wider/lower profile tyre and stiffer springs on the 250, the reduction in tyre noise is very noticable. The Proxes Four on the IS200 17" rims are also a lot quieter. Sorry I cannot comment specifically on the Toyo R32A, but my expectation would be an improvement on the Bridgestones for both grip and noise level.
bobc ...You were unlucky with the rattles...my 250 SE-L remains as quiet as the proverbial...as a matter of interest do you have the Mark Levinson pack?
Thanks for this information, I'm pleased to learn that I'm not the only one to consider the road noise levels to be so high. I don't have the Mark Levinson pack, the reason being that as I keep my cars for a short (ish) period the residual values remain very high, the addition of multi-media and sat nav systems would not have increased this value to a degree that would compensate for the initial outlay. The rattles appeared to come from the centre dashboard to start, then from the area (dashboard) directly infront of the driver and finaly the B pillar right by my ear. In fairness I think the Lexus dealer was well aware of these issues with other owners but obviously would not admit to it.