Regarding Cars. We don't finance cars, we buy them; we earmark money we put in savings for the next vehicle. Just because you get a low interest rate doesn't always mean you get a great deal.
We paid cash for our last new car (it wasn't available as a used model), but I don't think financing is always a bad idea. If you can put the cash into an investment account with a better return than your interest rate, it's a good deal. Right now though any guaranteed investment (like CDs or a money market account) is so low, it doesn't make sense to do it this way.
My car is 12 years old, so in the next couple years I'm going to have to start thinking about maybe getting a new one.
We can go on a $3000 vacation with little "savings" because we are extremely frugal in everyday life (see: 12 year old car). We don't have cable, I haven't been to a coffee shop in years, I don't smoke, we eat out about twice a month, we go to the movies less than once a year, I get my hair cut every 2 years, I don't wear designer clothes or get manicures and pedicures.. Basically, everything we do is saving- it is the way our budget is set up. Sometimes (like this summer when we spent a few months learning to scuba dive) we spend a lot and nothing goes into savings, so then we are more conscious about it for the next few months. We certainly can't take a $3000 vacation all the time, but if we want to, because of how we live our lifestyle without excessive spending, we generally can if we want to.