As far as the carseat goes, I turned ours around when my son was a year and a half. We don't have rear air in our Crv, and we live in Arizona. it's much more dangerous for my son to sit in 115 degree weather without air than to turn him forward facing at 1 and a half.
Sorry, I call bullshitt. You can start your small SUV five minutes before getting in and it will be sufficiently cool. Just like I start mine five minutes before getting in during the winter to warm it up. Not that hard and absolutely not an excuse to turn early, IMO. In case you can't tell, I'm a very big advocate of this and you will be hard pressed to find an excuse to make me think it's worth the risk of a child's safety.
It's crazy that so many people get defensive about this and start spewing excuses. If you did the research, you'd agree with me. I'm not making this shitt up. The AAP bases their recommendations on extensive research. The National Highway Safety Patrol and CDC back the recommendation.
Oh, bliss, look how you got me goin. lol.