that dealer is full of it.
1. Toyota's image does not agree with a "Supra" type machine in the lineup. It drinks gas and isn't family friendly. It's an exotic car that goes against the very image Toyota built.
2. If a supercar were to be made, I'd expect to see it under the "Lexus" brand. Class, a touch of the obnoxiously unnessary, power, etc ... this is perfect for them.
3. The MR2 and Celica are perfect examples of Toyota's image clash. A 2 door roadster and 2 door sports coupe isn't what they want to be about. Scion was created to place cars with personality into.