Take the picture of that BMW using your own smartphone and then just include a shorter disclaimer:
"We are an independent repair service not affiliated with any car manufacturer." That way you could change the picture and use the same disclaimer.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.
If BMW is so inclined, they could still sue you. Whether or not they will win cannot be predicted, but whatever profit your business is making will vanish in court costs.
Better you not do this.
Consult with an attorney to discuss all the details.
Genrally speaking, there is no intellectual property right in the design or look of a machine (in the U.S.). A photo that YOU take that contains no emlems or logos should be fine. A reasonable, short disclaimer would be better.
The foregoing answer represents general information only and does not constitute legal advice. Further, no attorney-client relationship exists as a result of reading or relying on the foregoing answer. You should seek sound legal advice from a competent IP lawyer.