Lots of abbreviations are used in cars. Here is a list. I got this from a tech site.
(R+M)/2==Average of Road Octane and Motor Octane and is the AKI of gasoline.
A/B or AB == Axle Back (in refrence to the s197 rear muffler location)
A/C COMP==air conditioner compressor
A/C==air conditioner...
:welcomenym: I have to say it again, some cars are not meant for yellow, but that one is sexy. Nice ride. And yes, you will always find something to do to it. From mild to wild ponies are great.