im trying to change my tranny fluid for my 2k3 6 speed max...

hit 30k miles (all highway which drives me nuts)

but anyways I am looking for where I would put an additive like prolong or something.

 

You are better off using a good quality ATF rather than using an additive. 99.9% of them have been proven as snake oil. Just be religious about changing and using good oil and you should be ok.

I am not sure if 03's are different than 01's but going syn is a good thing. More $$$, but better oil.

I cant help you on the dipstick location. I have a manual

 

The manual doesn't have a dipstick. There are two plugs on the side, one for drain, the other for fill. You will need to use those when changing the tranny fluid. When filling, get a funnel with a hose and have someone pour it in from above while you keep an eye on the fill plug and make sure it doesn't overflow.

 

I think you may mean a good quality gear oil instead of ATF. He said that he had a 6 speed.