The Best Car Subwoofers for you will be one that fits in your vehicle, one that you can properly power, and one that fits your budget. If size, power, space, and budget aren't issues, go with the 12-inch subwoofers. If 12s won't work, go with 10-inch subwoofers. If 10-inch subwoofers won't work, go with 8-inch subwoofers.