I've been thinking about doing some quick and fairly painless upgrades to my Volvo in an attempt to make it more fun to drive. I live in Hawaii and I'd like the chance to fully enjoy some spirted driving through some twisty mountain roads. The upgrades that I've been specifically interested are:

- Sway Bars- front and rear but I would like some sugestions on the diameter for the bars.

- Exhaust- Just a turbo back custom exhaust but i dont want anything too loud as it is my daily driver as well.

- Boost Regulator- I'd like to add a bit more boost if at all possible. I'm pushing about 12PSI as of now but I'm not sure what a safe limit would be for a stock engine.

- ECU- This is the last thing on my list because I know the least about them. Such as what brands are trustworthy and what settings would be the most beneficial for a my car after all the previous upgrades have been done.