At the oil change place, they always try to sell me a bunch of\ngoodies. Today it was the following:\n\n1. Flushing the oil system... \n2. Flushing the cooling system... \n3. Replacing the automatic transmission fluid... \n4. Replacing the PCV valve... \n\nThis seemed like an awful lot of flushing -\- of my money down the\ntoilet. I declined all of this stuff. Now for the question: Which, if\nany of these things, are worth doing? If so, how often or under what\nset of symptoms? Can I do the tranny fluid myself without too much\ncussing? I don't do the oil because the filter is inaccessible without\nputting the car up on blocks.