i have some ideas for some vanilla style cars.. here they are!:

Classic cars, from maybe the 1940s to 1980, cities skylines needs more older cars that are vanilla style, like a Chevrolet Bel-air, or a 1970's Dodge challenger or a Dodge Aries.

Muscle cars, we also need more performance cars like muscle cars, like the Chevrolet Camaro, the Dodge Charger, or the Plymouth Cuda.

UTE's: UTEs are probably one of the most underrated car styles there is, and there is a lot of beauty to them, so maybe the Holden SV6 or the Subaru BRAT.

Cabriolets or Convertibles: many of these are present on the workshop, but to my knowledge, there is no vanilla style convertible present, or even concepted at all. it would also be nice to see my CIMS actually driving the car, along with the convertibles you could also make roadsters, basically sports cars but convertibles, along with this aswell, you can make a targa, which is basicalyl a semi- convertible car, it usually has something in the back which makes it semi- convertible, this body style is more popular in porsches, but other cars also have it.

Foreign vehicles: maybe you should make cars that are exclusive to specific countries, like in russia, their blocky SUV designs and their normal car designs that have stayed around until now would be nice to see in my city,japanese kei cars would also be a good addition, since they are exclusive to Japan for their small roads in Tokyo, people would be some nice additions for some people that just want some cars for a specific country without losing the vanilla feel. some examples are the Trabant 601, the Lada Riva, the Mazda Carol, or the Honda life step van.

Different emergency vehicle variants, as of right now, you only have the UK emergency vehicle liveries for your vehicles, although it could be alot of work, maybe you could make the default police livery for your vehicles aswell?

MPVs, MPVs are SUVs but mainly made for transporting people instead of cargo aswell. and have a more minivan looking design.example: Mazda MPV or the Lexus LM

Pickups: Pickups are also a more underrated car type regarding the steam workshop, there isn't that many that are vanilla style at all, there is only one on the workshop that is vanilla style and i won't describe them because literally everyone knows what they are, examples: dodge ram 1500, chevrolet silverado.

Minibus: it pretty much is all in the name, but these kinds of vehicles are either a passenger van or a shrunk down bus, but i want to focus on the passenger vans like for example: the toyota HiAce

Liftback or fastback: these cars have a slope in the rear roofline of the car, which gives the trunk more space and more aerodynamics, they can be a coupe, or sedan, whatever! some examples are the porsche panmera, the audi a7, the volkswagen arteon, and the Kia stinger.

Limousines: i don't have to explain these.

Semi's: i don't have to explain these

Micro cars: micro cars are basically just very small cars, smaller than kei cars even, some examples of these cars are the : Smart car, Aston martin Cygnet, and the Citroen AMI.

CUV: basically a smaller looking SUV, examples are:Honda CR-V, Mazda CX-9 and the Jeep Grand Cherokee.


i also named the car examples at the end so maybe you could mix or use their body styles for a fictional car.
this took a really really long time to make, so maybe i hope you can get an idea or two out of this!