Hey man, just give up with this post. You don't know enough about cars, energy, physics, and your engineer friends are shitty engineers lol. Let me try to actually give you the information you seem to be looking for. From an engineer with a lot knowledge and experience in what you're asking about, yes ICEs are inefficient in general. It's because of the fuel. They have persisted because of the fossil fuel industry primarily. Most things in this world are decided on based on profitability, not efficiency or sustainability. It's a difficult reality to accept as an engineer concerned for our planet, believe me. Electric motors for cars are also limited because of weight vs. range and battery material requirements. Hydrogen is a promising alternative that is still not super high efficiency, but the fuel is extremely sustainable. You can electrolyze water to make it and when combusted for energy, it just turns back into water vapor in the atmosphere. Renewable diesel can be made to have much lower carbon emissions overall and perform similarly to conventional fossil fuel diesel.

You're pissing off a lot of people because you're undermining how much energy and effort has been spent to try and come up with a better design already. It's not an easy problem to solve, there are real physical limitations, you can't just make an ICE more closed loop or something, it is hard limited by the combustion reactions' activation energies and our ability to dissipate heat and we are at that limit. I suggest if you're genuinely curious about future thinking car designs, you consider the future of fuels first, as the energy source is a far more important problem. The future fuels will be: green electricity, green/blue hydrogen, and renewable biodiesels and hydrocarbon fuels made of sustainable feedstocks like used plant oils used cooking oils and such. That will set the physical limits of vehicle efficiency.

Features like wipers and lights can be reimagined but they must be equally or more reliable while being affordable to make any sense. You wouldn't just replace a mirror with a screen, you'd always maintain some kind of fail-safe for an electronic feature. The screen would need to be very robust with a backup power source or something, which is costly. Instead you see in modern vehicles a screen that isn't critical to driving ability doubling as a screen for other vehicle features; if the screen breaks, you're not at higher risk of being in an accident. Layers of protection are important in any safe design.