The "How to edit Vehicle files" guide was not updated. I know where the wheel files are located, but I do not know how to improve their friction. I'll take "Clockwise 533 17x8 Rear Wheels" as an example. The only thing I found that has the word 'friction' on it were: They were both 0.5 for every single wheel, not just this one. (I think) And I don't believe every single wheel has the same traction. Otherwise, that would be redundant. If I remember correctly, they used to be in the "//general settings" of the wheels. Now they are not. Thank you for reading.
That's the friction coefficient for the metal rims - you'll need to increase the friction of the tire you want to put on it. Find the tire set you want to increase in vehicles\common.zip\tires and increase the friction coefficient for those tires and do the same for the rear. To do that, do exactly what you've done with the rims as posted above, except with the tires.