I stopped by the Hallmark shop in the nearest mall to check it out. It does look very cool! I could not tell the exact scale, but it looked very similar to other typical die-cast cars, so I would say somewhere in the 1/43 to 1/48 scale range, so yes, it should work fine for 25-28mm minis.
I balked at the $20 price tag, though. My mother has a penchant for picking up these sorts of nostalgic "silly trinkets", so for once I'm hoping she picks it up.
Of course, now that there's finally one I would actually want, I'm sure luck will dictate this is exactly the one she'll skip... so maybe next week I'll have to suck it up and get one myself.
- H8