Yes you can cash out your warrenty if you do not want it any longer.
Funny but kinda f'd up story on my part, I had one on my last truck (02 2500) I lifted it and modded the crap out of it, so I decided to get my money back from the warrenty went to the dealer to cash out and come to find out 3 months earlier the company I had the warrenty through filed bankrupcey and if I wanted any money out of it I had to get a lawyer and file a claim with the company 2 months before. I never heard anything about this until then no letter or anything. I got totally boned I even went out and talked to a lawyer to see if there was anything I could do but I was too late. Be careful and research the company before you buy, the company I used was reccomended by the dealer I bought my truck through.