Yes, purchasing every perk on a car gets you one completed Car Mastery in Forza Rewards. However, only permanent perks count toward this goal, not the consumable perks (those that provide a benefit for a limited number of races), so you can safely ignore those. The cheapest way to complete them is to spend your points on “Common” (green border) cars, as most of these have fewer perks than the higher-tier (blue, purple, & gold border) cars. If my memory serves me correctly, I believe it costs 39 points (or something like that) to max out one Common car. There are a few Common cars that have more perks, though, so you should look and avoid them if you’re just going for Forza Rewards score. Also, be aware that it often takes several days for Forza Rewards to update.
The cheaper, more common cars have less perks in them, usually around 8. Sort your garage by price, usually the cheaper cars are the common ones. These are the types of cars you will want to max out since they take less points and are cheap to buy.
Whilst I would agree it is easier to max out a cheap car … wouldn’t it be better to max out cars that you get the benefit of the perks?
I would start by maxing out a “skill point earner” …this will also get you further points much quicker … and not make them seem like a chore
for me my skillpoint earner is Merc SL65 FE … it has a drift boost & a very high drift tap boost (9k per tap)… I drift its ass off around the festival circuit …tapping all the way
As it is drift biased it might not suit you but something will …wreckage /speed … FE cars tend to have tasty perks in there
then move onto cars you will frequently use in various types of races /danger sign /speed zone etc again the perk will benefit you and the mastery achievement will come
I just had to check if I had the car mastery!! got it after only playing for a couple of weeks