How To Determine What Speakers Fit Your Car

Difficulty: Very Easy

Cost:

The easiest way to determine what size speakers fit your car is by taking a look at the original speakers. Most vehicles have at least 4 speakers, 2 in the front and 2 in the back. If you locate these speakers, you can usually figure out what size speakers will fit.
Look in your vehicle's owner manual. All cars come with owner's manuals and all owner's manuals have information about speaker sizes.
Call or visit your nearest car dealership. Any service department employee at your car dealership can tell you what size speakers will fit your car.
Visit vehicle forums online. Peruse online message boards for your brand of vehicle (examples: www.m5board.com, www.toyota-4runner.org). These message boards usually contain the information that you are looking for. If you cannot find the information, post a new thread asking for the answer.
Visit online electronics resources like www.crutchfield.com. They have car speaker size guides for all vehicle makes and models that are free for all users.
Visit your local car stereo store. Any person working at a local car stereo store, or a big electronics chain store (Best Buy, Circuit City, etc.) can easily tell you what size speakers will fit your car.