I always got a kick out of driving with my bike on my last car. Putting the bike on the back tripled the value of the car which always makes bike people smile.
I can fit in my garage with the bike rack extended which is great for getting stuff ready the night before an early ride. I could never remove the seatposts repeatedly to transport it. I'd have to buy a torque wrench to carry around just to make sure I don't shatter a $200 carbon seat post. I'd probably still end up with the stupid thing sliding down into the frame when i'm like 40 miles from my car.
Some of the brands, or the tool suppliers, sell small torque wrenches set for the specific torque you need. I had one that fit in my seat pack or fanny pack easily. It is good to check the seat height regularly as a change can be a problem. On one long ride I felt more strained and tired than usual for that ride and for several days after I had terrible leg soreness that I never get. I went to the bike shop and asked them to check the height (they had my fit on file-now I have it too) and they found the seat fell one lousy inch. With it restored, I did fine.
I find removing the down facing left pedal very quick and makes putting the bike in the back seat much easier. It takes a few seconds with a 15 mm wrench (for the beginners, it has a backward left thread) and should not be put back on with a lot of force. I keep it clean and put light grease on the threads occasionally.