How does warranty for Nikon DSLR works (3 year warranty)?

How does the warranty for nikon works if I want to upgrade to better newer version. I bought an used DSLR camera with 3 year warranty. The camera itself is D60 and everybody now uses 3000 or 3100 DSLRs or even better D90. I love my dslr but the thing is it does not take good photos and its outdated. I need something new and fresh. I'm willing to pay extra 300 or 400 dollars for the newer version of updated DSLR! I do not know how the warranty works, but I bought my camera at local dSLr shop that still sells cameras and I need to have the upgraded version S. O.S.
Do you think the store or the manufacturer would accept for me to upgrade my camera to better version if I put in extra little money for newer better camera than Nikon D60 which works fine but does not take good photos.
The camera was bought about 1 year ago, so the warranty is still good! Does it the warranty works like this or not

Warranties are for brand new cameras. It doesn't involve upgrading, only replacement and repairs in case of a factory defect.

Your best chance of claiming for your warranty is at the exact same store where you bought your camera. I hope you still have the sales receipt and warranty certificate. The factory and any authorized Nikon distributor will not honor that warranty.