CD formats on Brain Salad 3-CD set

I have Deluxe Edition of ELP's "Brain Salad Surgery". It is a 3cd set. The 1st is compact disc audo, self explanatory, same with the 2nd.
The 3rd one; Packaging says, Audio: 5.1 STS / 2.0 LPCM Stereo, but the disk itself says, Superaudio CD & compact disk audio. Can someone clarify the formats? I was playing it in my wifes Acura with DVD-Audio 5.1 and it sounds great as expected. Am I only listening to it in 2.0 in her car..? Is it a dual layer SACD/CD? Does it play in DVD-Audio?
BTW: DVD-Audio is awsome in that car.
Just curious is all.
Thanks, John