Dueling Dragons are definitely two separate coasters for all the above reasons, plus they're DUELING coasters not RACING Coasters which are more of a single coaster than two. Think about it this way, a racing coaster is simply one with double rider capacity, rather like a two-lane road. It's a single road, not two seaprate roads!
'Nuff said, I think SFGAm will be the first to have 4 B&Ms. There've been several rumors that they want a Flooless for 2002.
You could say that SFGAdv has the most modern coaster variety of all the 3 B&M parks - Inverted, Floorless & Hyper. IOA has two Inverted & a SD. SFGAm has an Inverted, Hyper & old Stand-Up.
I'm pretty sure that SFMM, BGW, BGT will join the 3Beemers club.
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Home Park - Wonderland Sydney, Australia.