There are a few things you need to be aware of before you install that new part on your car.

1. Exhaust. Installing new exhaust is a great way to get more horsepower, but you might be breaking emissions law in some states. (Most notably California) The next time you get hit up for emissions you will probably get hit with a warning at least if you have installed a new exhaust system.

What is the best way to avoid this? Look for exhaust systems that have hi-flow catalytic converters which give more power, yet keep you legal. The only problem with these systems is they often cost more than a normal system. However, if you get one ticket for being over the emissions limit, the cost will be more than if you had just bought the legal system in the first place.

2. Radar Detectors. These are illegal in some states. Be sure you know if they are allowed in your state. There is nothing worse than a speeding ticket and a ticket for illegal equipment at the same time.

3. Performance parts. Some performance parts will shorten the lifespan of your engine. You need to be aware of what you are risking when you put a new performance part on.

Also, if you have a new car under warranty it is recommended that you wait until your warranty is up before making any modifications. Often, if you have changed anything about the car and then your transmission or any other part stops working, the dealer will refuse to pay for it since you have modified your car.

Some of you will go ahead and modify your cars while it is under warranty anyway, and there isn't anything wrong with that. Just be aware of the risks you are taking when you start to modify the car.