The dongle is very much necessary, Fuel map can not be further changed without it. As far as need it, well like Hobbit said, you paid for it, why would the dealer want to keep just another copy of the same thing.
It depends on which SERT you got. The new Pro Tuner with the RED button on it does not come with the cable and CD. I thought it did but when I took the time to read the cataloge closely I found out that everything is sold separately.:newsmile049: