What fluids need to be changed/flushed with the coolant?
 

Think I need to flush my coolant, someone told me b4, i should change certain other fluids like the differential fluid as well, anything else u guys suggest to tune up my car?

If you dont remember the last time the diff was changed, then change it. Same goes for the tranny, oil, coolant. Remember to drain the crap in the over flow bottle. I suggest having the oil cooler and the radiator professionally flushed if it never has been.

If you are following the Mazda Facory Service Manual Maintenace Scheduale than replace

Automatic/Manual fluid. Filter too for Auto's.
Diffential Fluid
Brake Fluid.

When replacing the Coolant. Awhile you are at It, replace the Fuel Filter which seems to be under rated and neglected part of all maintenance parts.:D

why do u suggest that? is that hard to do? or requires certain equipment?

i've read about the transmission fluid change, might get that professionally done...heard it's a bitch to do

where is the fuel filter? havent REALLY looked for it, but was wondering for the next time im under there.

Suggest the Fuel Filter? b'c It seems to be over looked, at least what I find.

As for the Tranny/Diff Fluid drainage, easy as can be. Providing you have a hoist. Go to www.fc3s.org and download the free FSM and see what I mean.

very easy to change tranny fluid, just run a line down through the engine bay to the tranny, then play the waiting game as that thick ass oil goes down the tube.
The diff would require a pump of some kind unless you want to open the fuel pump door and run a line down through there.
Fuel filter is relatively easy to replace, it's just a bitch to get those line off.

If your flushing the radiator out, take the opportunity while the coolant is out to replace the thermostat with a genuine Mazda unit. Aftermarket units don't have a good reputation for being all that great. Even if it's still good it's still a good idea to replace it before it lets you down. It's inexpensive insurance.

The Fuel Filter Is located at the very bottom of the Drivers side Firewall. It's bellshaped and mounted on a bracket.