Another Auto Transmission Problem
 

A week ago I'm driving with my friends and all of a sudden drive goes out while in the middle of an intersection. We coast to the other end of the intersection and tried to step on the gas. The car doesn't go anywhere and just revs up. I try in 1st gear and the car takes off just fine. Two days pass and my car is perfectly fine. On the third day drive goes out again. I take my car to my local mazda dealership and leave it there for three days. At the end of three days they don't know what is wrong and have to call in a 'Mazda Technician.' So I just took my car back and told them to call me when the tech comes in. The car runs fine except drive goes out randomly and slips back into neutral and makes a horrid grinding sound while idling. Reverse, N, 1, 2, 3, and 4 all work splendidly. Anyone have any idea what is wrong?

Not heard of that one. But I have noticed some other quirks in the AT.
I don't drive the car in "D" I use the steering wheel paddles.
I have noticed some "slipping" going into 3rd from 2nd. first thing in the morning.
Hope what you have is not something to look forward to.
How many miles are on your car?
In assume you have or the dealer has checked the fluid level?

31k Miles on my car
I check the fluid level once every three days since drive slipped the first time.

As for the 'slipping' going into 3rd from 2nd, I have never had this happen to me.