I'm not sure if this is what your looking for but this is what I use, I hope this helps, you may need to change the terms as we do a life time warrenty and you will of course need to change the name.! I also have a vehicle check list if you need that also.
EXTREME CAR AUDIO
Ph (XXX) XXX-XXX
We at extreme car audio promise we will make every effort to insure a quality, professional installation of your audio equipment. With over 30 years of combined experience and the will to strive towards customer satisfaction we will strive to give you professional results at a fraction of our competitors cost. We thank you for opportunity to serve you. But in an effort to keep the costs of installations and equipment down we require that you agree to the following terms.
This is a legally binding contract between extreme car audio and you.
I hereby agree to Release Extreme Car Audio and its employees from any damages that may incur directly or indirectly from the sale, installation or use of any auto sound equipment. This includes but is not limited to auto sound equipment that is purchased from us and installed by someone else. We are not responsible for damages that incur as a direct or indirect result from the sale or installation of auto sound equipment by extreme car audio. We are also not liable for any damages caused by defects or craftsmanship of the products or the accessories that are installed or used in your vehicle. I understand that extreme car audio will warranty the install for the life of the componets subject to the following exclusions, This warranty does not cover equipment that has been subjected to abuse, neglect, incorrect wiring, water damage or modifications in any way performed by anyone else other than extreme car audio .I understand that if anyone makes any changes to the installation of the equipment installed by extreme car audio, including but not limited to removing ,changing or adding car audio equipment will void this warranty. I also agree that any and all legal action that may result from a breach of expressed or implied warranties shall be limited to the cost of the original installation price. As a condition of this document any and all liability from coincidental damages are excluded. the remedy provided by this document is the sole remedy under the following terms.
I ______________________________ hereby authorize extreme car audio to perform the installation of car audio equipment in my vehicle risk free, without responsibility.