Disagree. I don't think financing a car ever makes financial sense. Look at it this way. Average car payment in America is around $450. You mentioned a $12k car earlier so let's assume that's what we've got in our rainy day fund. Our hypothetical car dies on us and isn't worth fixing so another car is needed.
Case 1 - Person keeps their $12k in the bank and finances a car. They pay $450 a month for 5 years and at the end of the 5 years they own a car they paid $27,000 for, but is now probably worth $10,000 or even less. They have lost $17,000 in the deal in depreciation. Each year they are spending $5400 for which they are getting a negative return.
Case 2 - Person takes $2k out of the rainy day fund and buys a reliable beater car just to get around. This person makes car payments to themselves (since he'd be paying $450 to the bank anyway) and in 4 months, the $2k is back in their rainy day fund. (This assumes they make no effort to save anything above the $450.) They can then take that $450 a month and stash it in a cookie jar (or an equivalent) and in another 8 months, they've got $3600 stashed away. So in the first year he's replenished his rainy day fund and has $3600 in cash. The $2k car is not likely to have lost a lot of value in a year. He can sell it, toss in the $3600 and buy a $5k car and pay cash for it. He drives the $5k car for a year and pays himself car payments. Now he has a $5k car that probably hasn't gone down in value much at all and has $5400 in cash. He can sell the $5k car and use it and the cash to buy a $10k car. Again, he's losing next to nothing in depreciation and in two years he's driving a pretty nice car he paid cash for.
Holy Moses. Those examples are waay extreme.
Case 1:
Who in their right mind would finance a car at 38% over 5 years? I sure don't know anyone who would. Because that's what a $450 car payment over 5 years is on a $12,000 car that you pay $27,000 for.
Here is a real life example pour votre education.
You have good credit. You've been responsible with credit cards and have payed off all of your loans and/or are doing so on time. You don't get reported to collections but you may have missed a payment once or twice over the past 5 years that happened to be submitted to the credit agencies (for the most part you aren't reported until 60+ days). Your score is between 700-800.
You have a pretty good relationship with your bank and they finance your car at 3.99% over 48 months or 4 years (mind you I know people with 0%-2% loans). Your monthly payment on a $12,000 car would be $270.89 and the interest payed on the vehicle would be around $1,000 total.
a. You have $12,000 in the bank. You took out $8,000 and put it in a savings, money market, or stock market and do well over 4 years of investing... You keep the other $4,000 in the bank for cushion and bills. You made money on the car you bought due to wise investing and even had plenty of cushion/rainy day money to spend on other necessities as well.
b. You have $12,000 in the bank. You took out $8,000 and put it together with your girlfriends $8,000. You purchase a HOUSE and you still have $4,000 cushion, a new house, a beautiful new(used) car, and a very happy girlfriend/wife.
Win, win, win.
Case 2:
I don't even know where to begin with this. Since you've inserted your 38%, 5 year car loan example... it's pretty much void.
For starters, you aren't going to find a reliable car for $2,000.