The term “coilover” just refers to a shock absorber wrapped in a coil spring, and coilovers are common car suspension parts in factory setups. But the ones you get from the factory are typically tuned more for comfort and cost saving than performance. So one of the best things you can do for your car’s handling is upgrade to performance coilovers, and by that I mean full coilovers the ones that include both the shock and the spring, so that they’re designed to work together. The great thing about aftermarket coilovers is that they preserve and can even improve your factory ride quality, yet they also dramatically improve handling. And most of ’em are adjustable via a little twisty thing on top, so it’s easy to dial in the setting that works best for you.
It has always amazed me that more cars don’t come standard with a strut tower brace. It’s just a metal bar, more or less, that stretches from the top of one front strut to the other, suspended right over the front of the engine in most cases. What it does is increase rigidity, which makes the car tighter and more responsive when you’re driving hard. Tell you what, if I buy a car and it doesn’t have a strut tower brace, I go right out and have one installed. Big difference for a small price.
Last but definitely not least, you gotta have the right wheels and tires, and here’s what I mean by that. The right wheels are big enough to fill out the wheel wells, but not too big–you want sufficient clearance so there won’t be any rubbing against the lip. And the right tires are basically as wide and low-profile as you can go within the limits of the wheels you’ve got. Just swapping the wheels and tires alone can give you a huge improvement in handling; throw in the coilovers and a strut tower brace, and it’ll be like you bought a whole new car.