IMO, the main reason why car stereos tend to sound better to many people is simply because most people (including studio owners who should know better) have their speakers too far apart. In a car, it's impossible to have the speakers too far apart. So before you try to make two wrongs into a right, try moving your speakers first. There is a definate sweet spot: too close and it may as well be mono, too far apart and the mix becomes a hole-in-the-middle.
It also possible that your speakers are too far away (which is also impossible in a car). Near field speakers are designed to sound good in the near field. Too far away, and you are hearing more room sound and this will color what you hear, especially if you haven't treated your room correctly.
An impulse response can give you an eq 'fix' that may be completely inappropriate and just make the sound worse. It will also add time-based 'ringing' (the reverb tail of your car). Despite the fact that we enjoy music in a car, the acoustics are really fairly crap. Apply this impulse response is not going to solve a bad acoustic problem in your studio - so there is no substitute for treating your room and placeing the speakers (and your ears) in the optimum position.
EQ should not be necessary - but if you want to go there, at least use a decent eq and not an impulse response of a very small space with it's own set of problems ...
Also factor in that car speakers, like hifi speakers, are designed to flatter, not reveal. A car is a noisy environment, and sometimes we find noise is comforting, and masks a lot of problems.
If you want a murky, noisy but fun sounding listening experience as an alternative to uber revealing studio monitors - have you considered some of those really cheap Logitech computer speakers with a sub? They are ridiculously cheap, and fairly hyped and noisy, but they are real-world toys that many people use, and your music has to sound good on these things too ...
My carbon footprint is bigger than yours.