Well, it's time for me to update this once again, and I apologize for that. The more I look my skins, the more mistakes I found. This time is the alpha channel on the DDS files of the static rims on the cars with colored rims (#10, #22, #23, #25, #26 and #33). You'll only notice the difference in the showroom, or when the car is stopped.
I hope this is the final update, I know is ridiculous to keep updating a skin -or pack of skins- which is relatively easy modding, thus it should be perfect from the beginning.