There are several here in the Stuttgart area. I just googled BMW 118d tune & this came up.
http://www.atb-tuning.de/shop/Chiptu...etail-2443.htm
When it comes to aftermarket sun roofs they were all the rage as a dealer option back in the late 80s to mid 90s in America. Quality of contruction & installation was hit & miss. Some developed leaks after a couple of years. All aftermarket sun roofs added considerable wind noise.
My current car does not have a sun roof & I dont miss it.
You can have an aftermarket parking sensor added. The one offered by VW (when I owned a Jetta TDI) was only about 250 euro installed. I am sure the dealer can provide one with an OEM like finish at a reasonable expense.
Good Luck!