About the coolant
 

Yesterday, I went to do the oil change, the man told me that my coolant is not the right one. It suppose to be RED, not GREEN. And it cost $90 to change it.

Is he right?

By the way, my car is 98' Audi A4 2.8 Quattro.

where did you take it? it is supposed to be red but the coolant is red in a highlander too. g12 is the correct coolant for our cars

he was right about the coolant but make sure he put in Pentosin G12 which is actually pink.

^yea

and why does it seem that everyone is having coolant problems?

As long as you dont have g12 mixed with the green stuff it'll be fine. It's gotta be either straight green or straight g12. Of course Audi recommends G12, but it's not necessary. It's just that when you mix the 2 together it can gel up.

is G12 better or is it pretty much the same thing as the green stuff??

G12 is probably better but when it comes down to it they both get the job done.

G12 has better anti corrosive properties for better protection over many years, its also said to be "lifetime" antifreeze, as in it never needs to be changed. but as long as you flush it out completely you can switch to green stuff without your car exploding.