you don't need anything in my opinion. most of the car will fit with low rubber block that it comes with.
however, you might want to pickup schrader tire valve tool as none of mine were tight on QJ from factory. along with that, you will need bicycle pump.
In my opinion, stud kit is more beneficial for track oriented car because those car's wheels will be on and off all the time and will make it easier to so. as for longevity, might want to switch out after few years on both stud kit and lug bolts regardless for street only driven car.
I agree with you on data but have to disagree on method. Spoiler does not add HP therefore dyno data is useless. It adds down force by having lunches on top of the spoiler so data should be more like how many Wopper it will fit /w drink or pints. This may not be definitive method so perhaps...
I think, if you only concern is alcantara & larger rear brake, you could buy premium and then replace seat with alcantara or buy base and replace rear brake. I believe replacing rear brake would be easier than seat.
My advice has always been "Invest on yourself more than car." when it comes to track driving. So doing minimal changes to make the car reliable and worry-free should be the goal, in my opinion. Also, you may learn more by adding less variables.
having said that, below are what i changed for...
Olympic is back on GT7! This is sanctioned by IOC. Last winner actually received an Olympic Gold Medal if my memory serves right.
https://www.gran-turismo.com/us/gt7/news/00_4319738.html
The absolute must have is a good night sleep the day before. ;) sounds silly but hard for some people.. some showed up with red eye but pumped in the morning and then requiring intravenous feed of caffein by afternoon. Get a good sleep.
in my experience, to control "loose" car to go faster, you will be closer to the edge of "in control" and "out of control". closer to the edge, faster than "not so loose" car but just slightly off the edge, it'd be much slower. of course off on the other side of the edge, you lose control...
It is very hard. It took me 2 breaker bars to unscrew it and i thought I was going to break something. having another person to hold the steering wheel helps.
it's on PS5 and even on PS4, not a lot of difference on replay. my earlier video on GT7 is done with PS4.
LeMans race is what every GT7 youtuber is talking about how fun it was. here's one from Super GT.
I certainly had fun, racing everyday on that race. :D