Originally Posted by wstar

It's not just parts cost, it's testing cost, and warranty costs. There's no getting around the fact that a pair of flexible hoses carrying the most vital fluid in your car is less reliable than keeping it all in the block. There's also no getting around the fact that if they added it at the factory, it would have to be warrantied just like the rest of the car. They would have had to engineer brackets and fittings and sheaths and whatnot to try to bring the reliability up to par with the rest of the car, and done extensive long-term-wear simulation, etc. I have no idea how to work out what that costs in the long term in a car price. Let's say it ended up being $1000 or $1500 (not unreasonable, considering they're selling an unwarrantied and less-engineered addon cooler for $700).

Car prices are cutthroat these days, and a grand here or there on the mfg side of things isn't chump change. This is before all the percentages for various markups and taxes too.