3050 is bang on about the additives. They work in the short term but require proper repair and a full flush very quickly to avoid more serious damage (usually even says that if you read the fine print on most of the bottles). Mechanic in a bottle, 99% of those additives that is, is pure hocu pocus feel good nonsense (usually just atf). the best one I ever read was a auto tranny additive that promised to stop slipping and smooth out shifts, anyone with an ounce of knowledge about auto trans knows the soft shifts are a result of slippage. So just how is it supposed to stop slippage (which gives you hard shifts) and smooth out shifts? Answer, it doesn't, its all in your head. You can stop a leaking radiator by cracking a raw egg into it, something called alumiseal, or hell even a healthy dose of uncooked grits will puff up and the pressure will force them into the crack sealing it for a bit. The result however is other stuff also gets clogged and eventually the whole system is compromised leading to much more expensive problems like heavy engine repair. AutohausAz (I feeling like a broken record on them) is a good place, BAV auto or any of the other guys listed here and other places. Just shop around buy OEM replacement (in some cases there are superior after market upgrades available), if your good with your hands and some tools these cars really are easy to work on. You'll get better results by not cheaping out because with most of this stuff you do get what you pay for. 3.99 bottle of radiator fix and a boatload of engine damage, a ruined car? = new car time. Or just spend the money fix it right and drive it 300,000 miles? Seems like a no brainer. As always good luck