There's usually a big difference between people who maintain their car, and people who care for their car. Of course most of this is dependent on a higher performance vehicle, but I've never even seen the maintenance section of my owners manual, and never will. GM doesn't know how I drive my car, they don't know what my fluid looks like in the future. These things are listed in there for a couple reasons, at the top of the list, to keep cost of ownership down, and a
recommendation of when to do certain services, to keep their warranty intact.
That being said, the dealership doesn't know the above things either, unless they actually inspected them (which they probably didn't). They are just going off of things they have seen on other cars.
If you keep good gas (brand, not octane: no costco, maverick, walmart, etc) then you are probably fine, and don't need a fuel injection service, although adding a bottle of cleaner here and there isn't a bad idea.
They probably hit you up for a combustion chamber cleaning (might have been part of the fuel injection cleaning), if you have a catch can, then that is not really needed, but if you do not have a catch can, then it can be very helpful. The burning oil will deposit inside your engine, and can eventually cause problems.
Transmission fluid can go bad way before the 100k, or even 50k mark, depending on how you drive it.
http://www.camaro5.com/forums/showthread.php?t=164430
Same with differential fluid.
The manufacturers of coolant recommend changing it every 100k miles, as the different ingredients can deteriorate over time and use.
So yes, they just want your money, but its because of things they have seen in the past, from people who just
maintain their cars.
Have them show you the fluid, compared to new fluid, and you make the call.
- Jeremy
