What is the preferrred way...

[goride]

Lots of different approaches here. No doubt if one doesn't work with my car, another one will. Thank you for your input.

[Crankin]

My seats fold down. I put the bike in, rear wheel first, drivetrain up. I usually have to open up the rear driver's side door, as well as putting it in from the trunk, to help maneuver it in from that angle, as although it easily fits in the space, even with the wheel on, it often gets twisted in a position that makes it difficult to slide in. I have to be really careful with the bars. I've ruined both bar tape and part of the hoods this way.
I didn't do any large group rides this year, where I had to drive to the ride, so I've only put my bike in my car maybe 4 times since March.

[OakLeaf]

My bike lays flat in the back of my car with the rear seats folded down.

But no matter what kind of space you have, unless you're putting it in a rear door with someone to catch the bike on the other side, you'll need to put it in rear wheel first, for the simple reason that once you let go of the handlebars, the front end will flop. So the bars need to be the last thing you let go of.