[special-K]

I agree with most of it.Only factory installed is factory installed.But,a factory installed sliding window was installed on the lot by a vendor.The reason the factory has quality control department is because it`s so huge and so many hands went into the assembly of one vehicle.That`s alot of links in the chain.When someone does the same thing and only that thing they can lose sight of the total picture,too.Not to mention the monotiny factor.Truck equipment businesses can be very high quality.They specialize in what they do and the equiptment they install is for serious commercial use.They have liability for the winches,plows,dump bodies,wrecker bodies,etc. that they install.The stuff is installed to make the owner money and take years of hard use.And,they have competition for doing business with area,and beyond,dealerships.If stuff comes back to the dealership too much,the dealer moves on to another shop.These are small businesses compared to auto manufacturers and know they need to maintain a high standard.There are many many truck equipment companies and only one GM.