There is no "auto-taxi" feature for any aircraft that I know of.

There a the DBS Airport GPS that can be used to guide you from any Gate/Parking Ramp to any Runway, or from any Runway to any Gate/Parking Ramp at all airports (as far as I know). The only thing wrong with it is that it will not necessarily guide you by the taxi route that the ATC has given you. But like a real world GPS, if you miss a taxi turn, it will rebuild the route from you current position. It will not move the aircraft along the route, you have to follow it yourself. I bought it a couple of years ago and it's pretty neat and I like it. They also have a Follow Me program, but I don't have that.

FS Dream Team have GSX, which provides a Follow Me car, but I rarely use it. I do use the "Just warp me  there" feature occasionally, when I'm being lazy, to get me to the Gate/Parking Ramp without having to taxi all the way.