A vehicle is not a good investment. The depreciation is incredible in the first year or two. As much as it stinks to take the bus I think you're doing the right thing.
A vehicle is not an investment. It is a tool. If you need one then you need one and it just comes down to choice.
And depreciation is a non-cash expense. If you keep a car for, say 10 years (my average has been 12 years) then the annual "loss of capital value" entry to your balance sheet is 1/10 the cost. You can balance that against the value to you.
In kombat's case, assuming a $20000 car, the annual cost is $2000. If he takes out a $13000 loan at 5% interest the annual interest cost is about $600 the first year and declines each year until the loan is repaid. The question comes down to whether he gets $2600 of personal value from the car...and how that amount compares to the alternatives of waiting, taking the bus, etc.
In my personal case I have found that with used cars I often spend more in maintenance. As I said, I tend to keep cars a long time, but I'm not convinced that is necessarily optimum either.