Did you know that customizations done to your vehicle that do not come from the factory are typically NOT covered on your car insurance? If you are lucky, your policy may cover $500 - $1000, but that may not be enough.
Typical modifications are: custom paint, custom wheels/tires/rims, exhaust, stereos/tv equipment, grilles, winches, etc.
Modified cars can be works of art with how they look and sound. This art does not always come cheap so make sure you ask your agent if you are covered.
If these parts are not itemized on your policy, your insurance company is paying you the cost of factory parts and no more than that. Also, Aftermarket Parts are not covered by Gap Insurance.
Your must first carry Comprehensive and Collision coverage on your vehicle in order to cover these parts. Second, you must add the specific coverage value for these parts. Having Comprehensive and Collision alone will not fully cover you.
It is possible to modify your car so much that the insurance company deems you too risky. For example, some insurance carriers do not want to insure a vehicle that has been lifted over 4 inches.
It is always good to have pictures and receipts of your Custom Equipment. Your agent may even keep this on file for you. Ultimately it is always wise to discuss with your agent how you will alter your car and how those alterations can be covered.