The 2008 Mazda 3 S is a moderately easy vehicle to maintain, but does have its share of difficult repairs. Checking the transmission fluid level with reliability is no problem, as the dipstick is easily accessible in the engine bay. Not every model includes this dipstick. Access for some of the tail light bulbs is easy, as you only have to remove one easy to remove cover for access. Other models will require you to completely remove the tail light housing. The engine fuse box is easily accessible toward the right of the engine bay.
Some things are problematic on the 2008 Mazda 3 S. Changing the headlight bulb will require to use a few tools to complete many steps for access. Other models will not require you to do this. You will have to remove a few bolts, and then peel down a panel, for access to the fog light. This will require you to contend with gravity as you complete. You will have to remove the air filter intake vent to access the engine air filter. Other models will make this much easier.
Hans Angermeier has produced over 100,000 videos showing drivers how to fix things on their cars. He has broad expertise on basic repair procedures covering the majority of cars on the road.