Seems to me you need to find a way to interest the gf in working on cars! Buy her some pink overalls or something and tell her how cute she looks in them working on the car. Maybe sew a MB badge on it. Cleaning grounds should be something she could do. And since she has WAY better fine motor skills than a big lump like you and can get her hands into smaller places, why she is just perfect for this kind of work. That's what you tell her anyway.

I knew a young lady that owned a 240D and wanted to learn to work on it. Not GF, wife would have objected. She more or less became an apprentice to me and we spent a lot of time working on her car. She did well and eventually had the car in good enough shape for her to drive it all the way across the country on her own.
Yeah the shrinking daylight thing is an issue. I have to get the new motor in the SDL so I can have the bay back to work on other cars.