How to unlock Tuning Shop
To unlock the Tuning Shop, you have to complete Menu Book 3, which requires you to acquire three specific European classic compacts: the Fiat 500 F ‘68, the Mini-Cooper ‘S’ ‘65, and the Volkswagen 1200 ‘66. You can acquire cars as prizes in the races specified in the Hints in the Menu Book itself, or else buy them at the Used Cars Pavilion. All three will become available to buy once you start the Menu Book. You have to do this manually at the Cafe, by the way, so make sure you remember to do so. And Menu Book 3 can only be started after completing Menu Book 1 (collecting 3 Japanese compacts) and Menu Book 2.
Before you go to the Tuning Shop, make sure you go to your Garage and select the car you wish to tune up. You also might want to visit World Circuits, decide what race you want to try next, and check if it has a maximum PP limit. If it does, then you’ll want to tune your car to as close to that PP limit as possible without exceeding it. When you buy your first tuning part, you’ll unlock the A Taste of Tuning trophy.
Tuning parts are divided into five increasingly powerful and increasingly expensive levels: Sports, Club Sports, Semi-Racing, Racing, and Extreme. Initially, only Sports is unlocked, but you can unlock the higher levels by collecting more cars and therefore increasing your Collector Level.
Generally speaking, tuning parts improve your car’s speed or handling, but all ting parts increase its PP. You can see how much a part increases your car’s PP by selecting that part and looking at the difference it makes to specs on the panel to the right. Generally, you want a balance between speed and handling. If you only buy parts that increase your car’s power, you won’t be able to control it on corners, and if you only buy parts that improve handling, you’ll get overtaken on the straights. Tuning Parts are automatically fitted when you buy them, and you can take them on and off in the Car Settings screen in your Garage.