Tips on Buying Cars: Keep car or Trade_In, 2006 toyota corrola, 2007 toyota camry

Question
I have a 2006 Toyota Corrola (50K miles, 17K payoff, I pay 365 a month) I drive it 120 miles a day to work and back. My kids complain it is too small in the back for all 3 of them so I want to trade it in for a 2007 Toyota Camry. If I put down 6000K on it and the dealer paying off the tradin it comes to approx.425$ a month, which I can afford but the question is: Is it better to keep a car until its paid off even if it means running the mileage to a huge amount, further lower the trade-in value or should I trade it in now, thus increasing my monthly payment to 425$ a month for 6 years ( adding 1 1/2 years of payments from what I have now)?

Answer
First suggestion: rent a 2007 Camry for a long weekend, and take the kids EVERYWHERE in it.  Make absolutely sure they'll be comfortable back there.  I'd hate to make an investment like this, only to find out the car isn't as roomy as it needs to be, or as big as the kids say they need ("Ma, this seat is TOOOOO small- can we get a Bentley?...").

Unless the back seat of the 2007 Camry is just HUGE, I'd have to advise to hang on to the Corolla as long as you can.  You already owe more than your current car is worth, by at least 35% (I sure hope you have gap coverage on the current loan).  Transferring that problem to another car is only going to make it worse, not better.  Yes, your trade-in value will go down, but guess what: your loan balance will soon start dropping faster than the car's value, so the problem actually improves slightly as time goes on.  Besides, what's worse: trading in a car that you have negative equity, or trading in a "hooptie" that's paid for.  The old, paid-for clunker at least has SOME equity, if only $1,000 or so.  But negative equity is worse than no trade-in or down payment at all; it insures you're starting out in a worse situation.

AND- ask yourself this: how often do all three kids ride in the back seat of that Corolla for any length of time?  If it's only once or twice a month, then those are the times you should be RENTING the Camry, not owning it.  If they're complaining during the short rides, just tell 'em what our parents told us:  "Hey, we're almost there...."