Off body carry sucks. I've had more than one case of people shot and killed while trying to get to their off body carry, as in the situations you typically need a pistol quickly you're under observation and unexplained movements get you shot. On person carry still sucks if you're seated, but at least if you get removed from your vehicle you still have it, if you're under direct observation reaching to unclip your seat belt is expected movement, and if you don't have an opening just yet you're still not known to be armed. Additionally, unless you believe yourself to be infallible, more gun handling in an enclosed space where it's difficult to avoid flagging yourself also occasionally leads to new holes in the body you wanted to avoid.
If you need to be comfortable, put it in your purse. If you want to give yourself the best odds of prevailing in the very unlikely event you need it, nut up and carry it on your person.