The devs used to add more substantial content between major updates - take the many 0.9 patches, which added a lot of stuff for the Hopper and D/H/Roamer. Or 0.21.3, which added loads to various vehicles (mostly the D/H/Roamer). However, I think with how long it takes for the devs to do backwards compatibility and with how much more complicated the game's gotten, we probably won't be seeing any updates like those (or 0.5.1/0.17.1/0.18.3/0.24.1) any time soon. Nadeox and Diamondback made two posts mentioning issues with smaller updates back in October of 2017, when the game was far simpler. Nitrous hadn't even been added to the game yet.
There was one but I don't think it was overly realistic https://www.beamng.com/resources/etk-i-hydropneumatic-suspension.28975/
The MR Turbo's much closer to the Renault 5 Turbo (both were MR hatchbacks and used similarly-small turbocharged engines), but I do agree. There's a reason why the Charmand 1304 B (an '80s French hatchback from the concept list) was cancelled - it was too close to the Covet. Similar issue with the Mk2 Escort probably being too close to the Miramar for the devs to consider adding. I know it's a fair bit smaller and ~200 kg down in weight, but that's likely not a big enough difference. Even the Quattro is likely too close to the I-Series - honestly, that could probably be filled by a coupe version of the I-Series instead of a whole new car. Considering it's yet to receive a refresh, that could happen in the future. I thought that might happen in 0.35-0.37, but to be honest, it might be a very long while before the 'Hawk gets remastered. I don't understand why it's the only vehicle released before the SBR4 (18 Sept 2015) to not be remastered or refreshed - maybe it and the Barstow will be remastered or refreshed together in some future update? To be honest, we might see more prop focus in 0.38 - the devs could finish remastering the rest of the old props. 0.37 was a massive success for an update with barely any new vehicle or map content (it's the first update to not have a new vehicle or remaster since 0.16, although you technically could count the GM limo as a new vehicle), so I could see the devs capitalizing on that success for 0.38.
What bugs? I'm not aware of any major ones, of course there are minor issues and broken mods, but that happens every time, is it worse this time?
Electric motors are not engines, so they work fine. The reason we are not making a hybrid is because the whole electrical system logic that makes the engine and motor work together is extremely complicated and we don't have time to properly research and implement it