Cold "water" temperature and diffrent sounding engine based on first time startup would be really neat. My currrent car which is a mazda 2, a 2023 model when you start it it goes into high rpm for a few seconds then "sings" down and rpm drops back to 700 or so from a few points up and continunes with the warmup process which takes like 3 mins or so. Assuming each vehicle would have it's own quirks during this process, that's what will make each one super unique.
