Welcome.

Plenty of build threads with the information you are looking for.
Handling > Breaking > Power is always a good guide when it comes to modifying cars.

Don't forget about the smaller things (i.e. bushings) as they can make a huge difference for a small(er) cost.

Best mod you can do is to get the car on the skid pan at the RAC Driving Centre near the airport, will let you learn how the car really handles before you push it hard.

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2015 Forester XT Premium
2020 VW Tiguan Allspace
teejay: If I wanted a comeback Id wank in front of a fan