Yes, that's how it works. If you are already upside down then going to a more expensive car will put you even more upside down. My cousin had a wife (now ex) that caused them to be so far upside down that they basically paid $40k for a $20k vehicle.
The best piece of advice I could give is to just pay as much as you can toward your current vehicle every month. If your payment is $500 try to pay $700, or more to knock that balance down. If I wouldn't have been paying extra on my Lancer I'd be very upside down on it right now, but I haven't even had it 4 years and I am now ahead of the game so if I wanted to get rid of it I wouldn't have to add anything to the replacement.