So, i have just came up with an idea. It would be really cool if we have Keys for the cars, that actually turn when you turn the car off/on. Maybe they could also have something like Key Chains: Here are some examples: And yes, i know, it would be hard, but it would be a cool little addition.
The Auriga Heron mod had a key with a little key ring that moved. Its little details like this that many games don't include that just make it look so much better.
But that doesn't make sense for older cars like the Grand Marshal, which clearly has the ignition that requires a key.