I don't think that RL needs V8 to sell well in this case. The recent RL has been around about 5 years or more. The overall styling has not changed with minor updating of luxuries and some powers. Still, I don't see Honda is pulling off this model. Thus, V8 engine is not really the point to me.
With TL now, has the aggressive and the power to handle with 530&330, if RL is going to take on 540, that will be somewhat suprising to me as a marketing. I think it is more like a competitor towards E320 or S80. With 300HP+ & AWD, it is going to offer about the similar comfort as E500, however, with a lot less money. So there should be a market for. Moreover, I do not believe that RL will be a much more massive production car like its sibling TL, therefore, power & superior road handling will not be the main issue but rather comforts and luxuries.
RL has never been on the emphasis of its power and handling. A reworked C35 engine is not too bad if it can furthur improve its oil efficiency grealtly and overall comfort of the car. With IMA debuted later, Honda should still manage some room to react with other makers
Just a thought... :thinking: