Width and depth is about the same, but the box is taller - not sure quite how much...
My pca tuner is since about 2 weeks living in the dash of my new Peugeot - I was pleasantly surpised by the amount of space below and to the sides of the DIN slot, so I decided to use the kit tuner and put the original tuner in storage.
The kit tuner would not easily have fit in my Polo...

Anyway, the original tuner is ~33-34 mm tall (roughly 1 5/16") and I believe (from a highly defective memory) that the kit tuner is somewhere between 60 and 70 mm tall

You could of course with a bit of modification put it into a flatter but longer box if you place the circuit boards side by side, instead of stacked on top of each other.

/Michael