I have a vague idea floating around in my head for a vehicle system in which each class of vehicle has a basic stat line and then to create variations of a class you pick from a list of adjectives.
Said adjectives would not be modifications (so cannot be removed or installed), and they would be things that are particular to that production model, and every one of that model would be the same.
There would be positive and negative ones, and any car must have the same amount of pros as cons (even if all of the cons are "expensive", creating a great car with an appropriate price-tag).
Adjectives might include:
Roomy: Fits 50% extra passengers
Cramped: Cannot carry trolls, has squatter level amenities, and don't even try making out on the back seat
Rugged: Less likely to stop running when taking damage
Tempremental: More likely to stop running when taking damage.
Robust: Extra body
Flimsy: Less body
Cheap: Costs less
Expensive: Costs more
Ubiquitous: There's a million of em on the street (bonus to go un-noticed, availabily and repair cost)
Sore thumb: Rare enough to attract extra attention, availabilty is higher as are repair costs)
Economic: Increased fuel efficiency
Gas Guzzler: decreased fuel efficiency.
Crammed: less modification slots.
Rigger's dream: Extra modification slots.
Fast, nimble, nippy, solid, steers-like-a-cow,
A pair (positive and negative) of adjectives for every stat (including "stats" that are not in the statline such as fuel economy or number of passengers etc)
The qualifier "Very" can be used for vehicles that have the same adjective twice (maybe have "extremely" for the same mod 3 times?).
Then to describe any production vehicle you can simply list it as a character might describe it.
"The Jackrabbit? Oh sure, its an ubiquitous, cheap
subcompact, but its cramped and flimsy."
"The Shin-Hyung? My bud's got one of those, its a nimble, nippy, greased
sedan, a rigger's dream but not-so-smart, a gas guzzler and very expensive"
***
Modifications would still apply of course, including factory installed modifications. These would only be for defining the differences between production models. By only needing a simple sentence for each type of vehicle within a given class, you could print the stat block once and then just list some example descriptions for particular models - and it would make it very easy for a GM to create other models on the fly.