When parking in a lot I always back in. I am able to confirm that the spot is clear and then back in. When it is time to leave there is no backing up required, I can see where I need to go. The problem with this technique is that most people cannot park/manuvuer their cars. Watching drivers trying to navigate their cars in reverse is hillarious, it really exposes their lack of skill. When parked in my garage I make it a habit to confirm that the area behind my truck is clear. To do this I walk around the back of my truck to get to the driver's door, never walk in front. Driver's need to focus on the task at hand.

There's someone who's taken YD training.

I'm with you. And now, more out of necessity than anything else, I back into parking spaces. With the top up (like most roadsters), the MX5 is pretty crappy to see out of in reverse. I take my time, use my mirrors, look over my shoulder... stop and correct if need be. I can usually nail it first time, but I have no shame if I choose to pull forward and take a second attempt to make it perfect.
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MDX5, the problem with those systems is a) when people become entirely dependent on them and b) when for whatever reason they can't use them (ie. snow build up on the camera or sensor; electrical failure or simply driving a different car) and they carelessly just back up without due care.