This unit does not need any additional modules like most other systems for sale. It also uses your factory remote. It retails for $300. If you purchase it, I'll send you the manufacturers website where the link and instructions are all accessible. I'm selling with no return due to it being electronics and have no way to know if it was installed wrong and damaged. I never installed due to not wanting to take my car apart and void any warranty. I had the dealer install one for me.