[swordtart]

I think your mm values are actually cm - 0.84 mm is very small :)

I understand your aim, I just think you are looking at it the wrong way. If you are making a scale model then you make it to the same scale as the terrain which is tied to the movement system and which is 180th scale.

Unless you are using a grid there is no disadvantage in using different sized bases. You could also use a 1 1/2" base as the standard if you want to got that way and the rules already cover those. Personally I prefer the base to occupy the footprint of the vehicle so that I can better asses ranges and collisions (but that is my particular OCD).

You are also using "realistic" sizes for vehicles, but these relate to modern vehicles and CW vehicles are retro-future. The van trailer is not 48ft long, it is 40ft long, it states that explicitly in the rules. Rather than trying to adjust the scale to fit your worldview you could simply adjust your worldview to fit the scale (and worldview) you have been given.

The rules don't say how long a 2035 compact is, but it isn't the same length that a 2022 compact is. We know this because in the chassis and crossbow rules it notes that 2035 duelling cars aren't as "roomy" as the C&C cars (i.e. 80s-90s at the time), penetrating bullets can pass through C&C cars without hitting internal components.

In an Austin Mini (10 ft long), you could fit 4 people (The 2 of front ones have full leg room and thus are arguably 2 spaces each), an 80 cid gas plant and some cargo (4.2 cu ft not including the cargo bins in the doors). You can't fit all that into a subcompact so a CW subcompact is a somewhat smaller than a Mini. As artwork in the VGs tends to show more rectangular slab sided vehicles the setting is telling you that your CW subcompact would be shorter still as the Mini's engine extension should be merged into the main body of the vehicle (the Mini should probably classed as streamlined in CW terms).

I am also autistic and I have found that you can't always "fix" the broken rules. Sometimes the right solution is to follow a new rule which is "that the rules don't apply here".

Obviously you are free to follow your own path but given the lack of detail you are going to be able to achieve in even a 180th scale vehicle, reducing the scale still further to 1:220 seems a lot of effort for no actual benefit and actually introducing different inconsistency.