Most other major car audio head unit manufacturers size to fit the Toyota dash. You can see a clear size difference in Marks installation here -> http://mse.ufl.edu/~mark/empeg/pages/P1010019.htm
However, empeg is not to blame for this. To make a pull out unit fit in this space, the unit would have to be about 1/2 inch smaller side-to-side.

I haven't had any problems fitting Mk1 & Mk2 into my '92 Toyota Camry. In both cases the cage fitted in nicely. Only difference I've noticed is that Mk2 slides in the cage much smoother without scratching the empeg borders as much as Mk1 did - but I believe this is an overall feature on the Mk2 cage and is car independent.

Kim