I haven't work fully on it but have started removing excess resins from some parts.  IMHO, the parts on the whole are pretty well casted.  As the name implies, it covers the entire driver's compartment and nothing else.  Here's a list of items included:

1) Frontal glacis plate - looks like an exact duplicate of Tamiya's part except it included the interior details (detail is nice here though not super sharp).

2)RHS and LHS firewalls - not much details here except for a few bolts and transmission sockets.  Details ok but not sharp.

3) Floor - pretty basic with the huge "trapeziod" block where the transmission block's connected to.  There are a few minor details molded on the forward areas of the floor.

4)Transmission block - very detailed (IMHO)

5)dashboard - pretty nicely molded

6)two nicely molded seats

7)four inner periscopes - detail's pretty ok  however, the instruction only required two - I've no idea which two I really needed and what the remainder two's for.  2 same, the other two is uniquely different from the rest.

8)inner ventilator piece 9) 30 cal inner half to be attached to the inner side of the glacis plate.  You'll need to find a better detailed half of the 30 cal.  Maybe Collectors Brass?

10) Fire extinguisher plus it's attachment - the dials on the gauge is also molded.  Overall detail is ok but not sharp.

11) instruction sheet - drawing's ok and pretty tale-tell except for certain ambiguities - which periscopes to use, where exactly should the seats and fire extinguisher be located.  I suggest relying on good references for this.  It does include a list of parts to be painted in the appropriate colors - that will save you lots of questioning.

Above's the run down on the parts.  I've tried dry-fitting the firewalls, floor and transmission block into the altered Tamiya lower hull - fitting is not perfect and may require a bit of "tunning" into.  Anyway, the instructions did caution about this area.  Though I'm not a M5 expert, I believe that painting after built-up, this interior will enhance the M5 kit a long way!  Furthermore, I believe this is the only interior for the M5 in the market??  (I think)

3 and 1/2 stars for this conversion because it's a tad pricey, and the instructions and moldings can be further improved upon.