If performance and power is the only thing you care get a used turbo .
I have seen some 2-3 yr older cayenne turbo's for the cost of V6.

 

Had a v6 for a loaner and there is no doubt that you could live with it, but when spending this much money for a performance SUV why skip the performance??? V8 or turbo is the only way to go, otherwise you might as well stick with your Lexus.

 

No way....V8 will take my budget to another 20000 .
Cayene v6 is way more powerful than RX 330 , BMW 335 , and may be some 5 series .
I plan to buy Audi R8 in 4-5 yrs . Will talk about performance than . This is kid hauling go to work car . Burmester is must ..., So is other gizmo and performance plus package .

 

a 355 and a 5 series are faster also if u compromise u could get it.
but i get what u mean its not what you need .
goodluck !