Performance
1: Corsa Exhaust, the car now sounds as good as it looks, super agressive sound when you stand on it

but no heavy drone when driving down the highway. Bolts right in unless you own an '09 like mine so you need to have some fab work done to keep those sexy '09 exhaust tips!
2: Volant cold air intake. Engines need to breathe and now that it 'exhales' well via the Corsa, it needs to 'inhale' equally as well. Easy install, Combined these 2 upgrades add around 25 hp
3: Rear Sway bar, used the factory V sway bar, firmed it up in the rear, easy to install
4: new tune range for the computer, I found the car liked to often be in one gear too high (ie in 4th when it should be in 3rd) and wold be lazy, had to get my foot into it to make it kick down. New tune optimizes preformance, keeps the car in a mor responsive range in 'city driving' likely at the cost of a certain amount of fuel mileage but I am driving a sports performance car, not a family sedan.
5: Replaced Run Flats with regular type summer performance radials. I carry a repair kit and mini compressor just in case.
6: Get a Battery Tender, if the car is going to sit for any length of time, plug it in. If the car goes out weekly at worst; not necessary to plug in, but for the winter or extended vacations etc it is a must have. There are leads that stay on the car so you just pop the hood and plug in. Our Harleys are the same, part of the fault is the vehicles monitoring/security system, constant trickle of energy being used.
Other neat stuff:
Wind Restrictor, I got one with the brake light/ running light option, rather 'cool' when cruising top down at night but annoying at night if the top is up as it reflects in the rear widow.
Trunk lid liner, nice touch then the lid is up, classy addition to a classy car!