The one that went out a couple weeks ago on my mom's car, is the right rear. It's probably been used a total of 15 times in the 2+ years she's had the car. It just fell down one day, for no reason. As GTPluv said, you'll be a pro soon enough.
'90 Acura Legend LS V6 2.7 5MT ^
'87 Acura Legend V6 2.5 5MT
'94 Saab 900 SE V6 2.5 4AT