I don't think it's a jack on the right mudguard - it looks like it's meant to be a mallet or some other kind of tool. I think the point is that there should be a jack in that position on the Panzer IV, and it's worth making it a separate part.
The kit otherwise looks very fine. The details are sharp - especially the non-slip pattern on the mudguards, the tools and the bolt detail - and the lines look right. Excellent paint job too. I'm not entirely sold on the figures, but the commander from the forthcoming Panzer crew sprue looks good.
I'm not sure about the stowage. It looks rather stiff and unnatural - designing this on a computer still isn't quite working. It's also not really typical of Panzer IV stowage, which tended to feature boxes, crates and jerrycans rather than soft stowage like this. And, increasingly, lots of spare tracks.
I think it was mentioned earlier that the roadwheels on the Ausf D and Ausf E were slightly different (the Ausf D didn't have the extra dimples on the hub), but it's not going to matter in this scale.
Really looking forward to this kit, along with the early Panzer III. But I think the original Rubicon Panzer IV still looks good - it's certainly nothing to be ashamed of!