My question is that I finance a car from a dealer that cost me around
$11,000 but the thing is that I want a another car from a other
dealer,I want to know if I can trade the one that I have right now
even that I owe $11,000 from the other dealer, are they going to pay
the full amount for my car and give me the one that I want because it
cost around $16,000

A bit more info would be helpful for precise response-- current car's
make, model, year, equipment, date purchased, MSRP, negotiated price,
amount financed, rebates, loan payoff amount, and info on the vehicle
you want to buy for 16K.

in 1995, I had a friend who bought a relatively nice new minivan for
about 14K and change. Three days later she decided she wanted the
extended wheelbase version with a few more options that sold for 17K
and change, almost exactly 3000 dollars more. The dealership was glad
to make the swap for her... after giving her a bit more than 11K
trade-in for her three day old van. Between the depreciation, tax,
lost rebate (no rebate on the bigger van), lost title and registration
fee, the added cost of the bigger van, the added road tax, and the
bigger loan with a slightly higher interest rate, her decision to
change cost a bit under nine grand.

Being as you're hoping to buy from another dealer... the previous
dealer will not like your decision.  They will not give you $11k and I
highly doubt they'd even give you $10k or even $9k for the same car
they just sold you for $11k.

If you try to trade your $11k car in to the new dealer (where the $17k
car is), the typical trade in value is between 5/8ths and 3/4ths of
what they expect to be able to sell it for.  In this case they will
probably assume they can sell it for about $11k so they will offer you
approximately $8k for it.

Your best bet is probably to keep your $11k car and come to the
reality that mistakes happen and often cost us what we really want. 
However if the $17k car is really worth $20k to you then trading in
your current car and shelling out the big bucks to pay off your
current loan and getting a new loan is of course an option.