I think it would be a good idea to allow the user to change some aspects of their vehicles, such as the M4A3 that in the game has HVSS suspension but there were some M4A3 tanks with VVSS suspension or also the barrels of the cannons that in some sherman tanks had one with an air exhaust at the end of it and others with a smooth barrel outside, like the t-34, or another example would be the Sturmtiger that had 4 variants for its barrel, the first smooth, the second with 4 rods, the third with a crescent moon and the fourth that was one with a ring surrounding the true part of the barrel as well as the previously mentioned third variant that was a half moon ring.
another example would be the turrets of the t-26-4, t-28 and t-35 (in this case I will focus on the t-35) the t-35 had 2 turret variants which were really on the same base as the t-26-4 and which the only thing that changed was the part of the gates that in a variant was more similar to that of the t-28 of 1938 that had a rotating flattened cupola with the capacity to occupy a DT machine gun of 7.62mm to a specialized slot to support a mount for this machine gun and in addition to this kind of dome there was also a square gate next to this dome and the other variant is the one shown in the set just an elongated gate and rectangular in the middle of the turret, in addition the t-35 also had a different exhaust pipe, since instead of being elongated as shown in the game there is also a smaller variant but with two exhaust pipes.
There are even scale models that help me verify it and also of course, real tanks, these examples and clarifications are just some of many more that there are that could help improve the customization of land vehicles. But I have more ideas to share with with the developers of war thunder and with the community