Just found this link, Comprehensive Chevrolet, Saturn, GMC, Hummer, Cadillac, Buick, Oldsmobile, Pontiac, Geo, Dodge, Plymouth, Jeep, Chrysler, Ford, Lincoln, Mercury, Mazda Truck, Mercedes VIN Decoder
Lists all RPO for your can with VIN. GM dealers use internal database.
Was helpful since I bought my car used and didn't know exactly what was in the car when it left the build plant.
Thanks for the link. Didn't work for my vin, but I bookmarked it anyway. Luckily I have the glove box sticker so I could verify my car does in fact have the WHB option. Looking through the service manual I kept coming across w/ & w/o WHB but no explanation as to what "WHB" was. For future reference (hopefully Google will index this post), WHB on an Aveo is GM-lan which requires a CANdi interface module for the Tech 2 to communicate with.
Didn't work for my vin
I think it worked for my car... not sure what to make of all the jargon on that page.