Not going racing, but want a more enjoyable car for commuting? Then concentrate on things that make you feel good, but use restraint. Huge horsepower for commuting makes zero sense, but a great sounding exhaust and intake system with nice tires and wheels would make most drivers feel better about their commute. But, make sure you buy a quality — legal exhaust system as you still have to pass emissions, plus you don’t ugly sound of mufflers that fall apart from vibration.
Speaking of sound, some cheap exhaust systems can be really annoying due to droning inside the car. Cold air intakes must not allow water to enter the engine and, on tire and wheel combinations, seriously consider tire profile. You see the bigger your wheel, the smaller the sidewall of the tires, and for a daily driver that can be a problem. If you drive in areas with rough roads or potholes, tires with very small sidewalls can lead to repeated tire and wheel failures. When a tire hits the edge of a bump or pothole, the tire has to compress to absorb all the force of the impact. This causes excessive energy to be transferred into the wheel, cracking or bending it. Those same forces can also pinch the tire, causing bubbles to form on the side of the tire. Some restraint when modifying a car prevents problems in the future.