panzerguy,
My first response was going to be about the pak being clean and too much snow on the tires...before I did, I read other forum responses...we all seemed to notice the same thing...that's why we post our own work, right? It's obvious you live where it snows a lot and you know snow tendencies...I do think you need to add some "melted" snow though. I work with the same snow from the industrial size "spice" bottle you buy in the model railroad section...real happy with it, FYI..it mixes well with the scenic glue recommended on the container or thinned elmers. You can also mix it (w/o the elmers) with varied amounts of thinned future to replicate melting snow...you will need to add/dry/repeat to get the look you want, but it works great. (tilt the model to accelerate melting run-off).
Superb figures by the way...hate you for that one...my figures are amateur at best.