There is still a fair bit of clearance for the rotors so I doubt cooling would be an issue, they'll still far out perform the factory brakes. And true, this upgrade isn't as good as the TRD which was designed for performance but like you said it will come very close and at about half the outlay (unless you want to buy everything new from Toyota, in which case the TRD is the better option) Yeah right well if there is still enough room to make it all work fine then you have done a top job. true the TRD package is designed from the word go to stop cars hard and fast all day every day and things like its 32mm diameter rotors and aluminium callipers attest to this but the Kluger set up is a fantastic middle ground between the standard package that stop the car well for day to day use and still stands up well for a couple of decent stops and the TRD package that stop Aurion very hard for days. For the dough it will cost it’s hard to go wrong! Improved performance and looks for a very reasonable outlay!