Well, I can't say with certainty that TechniSat/Preh units can't work with the existing amplifier. But if we go down the path of assuming they can't, your choices are:
- Keep the existing unit and get a MIB2 amplifier (which should have component protection that needs to be removed if used)
- Get a Delphi MIB2 unit and keep the existing MIB1 amplifier
- Get a Chinese Delphi MIB2 standard special unit (i.e., the one discussed in this thread) with a 9.2" display and keep the existing MIB1 amplifier; North American maps and SiriusXM will not work. You are able to keep the existing amplifier in this case as the units are manufactured by Delphi. I think two people in this thread have audio working on 2015 Fender cars with these units.
- Get a North American Harman MIB2 High with a 9.2" display and get a MIB2 amplifier (which should have component protection that needs to be removed if used)
I have read that some people say that MIB2 units working with MIB1 Fender or Dynaudio is kind of a hack that may not produce the best audio quality, but I have no data to substantiate that claim.