The key to performance (Road) motoring is.......
1. Remove weight
2. Better grip from performance tyres
3. Better brakes
4. ATB LSD
The key to performance (Road and track) motoring is...
1a. Driver tuition
1b. Remove weight
2. Better grip from performance tyres
3. Better brakes
4. ATB LSD
5. Anti Roll bars
6. Fully adjustable coilovers with adjustable top mounts
7. Performance map and full bolt-ons
8. Lightweight wheels
For track focused performance add a full strip out, race seats and cage.
Lots of other bits that you can add too, but they are just "icing".