The trick is really to get a scanner that will do the deep codes such as transmission reset etc.
Other than the $800 etc options that comes with an outdated 2nd hand laptop and, to be bought extra, expensive connectors for the round din type connector I havent found any other option. The OBD scanners only address a part of the MB error conditions and definitely wont ever help you to reset e.g. transmission errors, which is unfortunately quite important. If anyone know of recent scanners that can do that please post.