To clarify, McIntosh is a home/profesional amplifier and speaker manufacturer. About 7 years ago decided to take on the car audio market with some sucess. But unfortunatly they do not manufacture their radios. They are made by Clarion. Their amp are extremely impressive. I have use them previously in my competition T-Bird.

 

I own and run quite a bit of McIntosh, and Nakamichi hardware both. The McIntosh amps are super, I have three of the 602 amps in the Nissan right now, and they are very sweet; still have a 446 in the shop. McIntosh headunits are indeed made by clarion, but are not duplicated by Clarion in their own line, no analog pots on Clarions!
I have seen a few of the MC406 headunits in competition, but more Nakamichi CD-700 units by comparison.
Nakamichi is making a dedicated return to the cassette market with thier newest high end stuff, the TP-1200 and the 1000td.
Kinda interesting-