I need to know if 2010 C300 with basic options is wired with memory seat.
It would be helpful if I could get diagram or photo to do the retrofit.

i got that model and i do have 3 memory settings. diagram i can't help you there.
good luck

gonna need at least P1 package for memory seats

I believe the basic model only has power seats, you need the P1 package to have memory.

What you need to figure out is if you can hook the memory module up to the stock power seats and where the module is. I is probably going to be in the door since that's where the buttons are. If you can figure that one out then you will be closer to getting memory seats in your stock model.

The memory seats may be more complex than what you expect. In the P1 and P2 package, there may be also motorized lumbar support. In the Euro 2 version, at least for 2010, there is memory for both the driver and the passenger, and the memories save the setting for the lumbar support. Although another change in 2011 was the elimination of electric lumbar support for the passenger. Not so simple then.

So there is no guarantee to think that the memory module for the seats is included in the basic model. It is entirely possible that the P1-P2-E2 module includes the headlight washers memory which operate every tenth windscreen wash. If you decode the VIN, you may find that your W204 was built on an entirely different line than the US P1 and P2 lines.

On yet another production line is for W204s that have the installation of the HK system, which requires fiber-optic for the rear subwoofer amplifier feed.