I'm not a good "stock picker" either, that's why you should get with a good advisor. I think the reason why people get into such a big financial mess, and make foolish investment decisions is because they don't spend enough time planning or seeking good advice. Sometimes you don't know what's best for your money, especially if you're going to "invest" into real estate where you have a capitalization rate that is negative. Find someone who is good, has a proven track record, and someone you trust. Referrals are usually the best way to get all of the above.
As for the car, that's an opinion. I could tell you that you could buy a $5,000 beater that will get you from Point A to Point B and you could pocket $15,000 for other reasons. but obviously, $20,000 is your limit for a car, that's preference. There are people out there who don't have the luxury to buy a $20,000 car. I simply prefer Porsche at the moment because of the reasons I stated previously. I haven't bought it yet, but I'm thinking I may in the next month. It's a real beauty. You see, I'm not looking at a Porsche as an "investment", it's a consumable good. That's the difference between a rental property and a sports car.
See you want to spend your hard earned money on a house to live in, even if you will lose money because of it in the coming years because of market factors. I could say, "Hey, that's dumb, put the money somewhere where it will do work. Renting would be better for your family's overall financial health." But I didn't. I only commented on your "rental parity" question.
I think money is made to be spent on whatever you like. I also went to Paris last year for 2 weeks with the wife. We could've had a "staycation" like a lot of Irvine-ites tend to do because of their lack of disposable income after housing cost, and it would've cost a lot less. But like a lot of consumable goods, it's up to the person who is buying to determine the real personal value to themselves.