I think, as a petrol head, sooner or later you'll find yourself drifting back towards Autotrader. Moving on to the next car is inevitable. I suspect for most, the Lexus F brand (outside of the L-FA) doesn't give enough to keep ownership interesting forever. But that's true of most brands.
In an ideal world, wouldn't we all have several garages and at least 10 cars? 🙂
Regarding Porsche. I owned a Boxster S and drove lots of 993s and 996s. As already said, the steering is mega and being a Porsche, they do feel special, but I certainly wouldn't want to drive one as a daily.