Land Rover variants are the next vehicle to be released. That will allow us to remove the Land Rover pack we use - one less mod needed. After that, I believe we are going to overhaul Cleggy's Ridgback quite significantly and include the Wolfhound and Mastiff at the same time (as we have the models). Again, one less extra mod needed.
We also have a MAN troop transport truck (not a vanilla truck reskin) that we'd like to do as no one else has done it and we lack a truck. We do have a Bulldog model (again from Cleggy), so that will probably get some attention when we get off the wheeled vehicles and move onto the tracked (we also have a Warrior to do).
On the subject of the Challenger, the model I have / the two I hope to have, are better models than the one recently released in the CUP update. There is only room for one slightly lower quality model in our pack (unless I can find a better one between now and then) and that is the Scimitar. Right, Lifetap?