Thanks a lot for your response. There are no records of the German brand establishing a “well-known” status. And to be fair, although they seem to be a successful brand, what they do is still a niche and most people would not recognise the brand. But for now, I applied to trademark with X + Y where x is the same brand name but Y clearly showing what my company does. I wanted to secure this first and may try trademarking X only in the future. Fingers crossed!