Hot Wheels has worked with Sonic themed cars before. This time, they made a...strange car and painted it so that it looks like it might be a relative of the Sonic All Stars Racing / Sega sponsored car Danica (seen here on the card) drove in the race. This is the "Danicar".
Why didn't they make a replica of the actual car? This car is unusual because if you look closely, it has 6 wheels. The front is a smallish fin & the engine is sort of exposed in the back while the driver gets a cockpit type area. It's still got the Sega / Sonic & GoDaddy branding/logos, along with some green flames.
This could be gotten as a pre-order bonus at GameStop for Sonic AllStars Racing 2...but where else can you find it?