Here's my take on how most premium car shoppers view the top 3 naming conventions, plus Caddy (and why Lincoln has the weakest alphabet soup naming and coincidently a sales decline in booming lux market to go with):
BMW - core products such as 3 series, 5 series, 7 series, X series are well known by even casual premium car shoppers
Mercedes - core products such as C-class, E-class, S-class are well known by even casual premium car shoppers
Lexus - core products such as the RX, ES, IS, GS, LS are well known even by casual premium car shoppers
Cadillac - core products CTS, Escalade, SRX are well know even by casual premium car shoppers
Yes, surely BMW, Mercedes and to some extent Lexus have decades of history with these naming conventions, no wonder they are remembered by so many.
Lincoln - viewed by most premium car shoppers as the MK-series of rebadged Fords (the alphabet soup that premium car buyers seem to be ignoring when actually spending real money for actual cars), with the Navigator standing alone somewhat as the fancy Expedition. Every model starts with same 2 letters (MK, exception being Navigotor), no top-tier premium automaker does that and for good reason too.
Yes, it's easy to be critical of any alphabet soup naming conventions but some do it better than others as noted above and I'm not suggesting BMW, Mercedes, Lexus (3 very strong selling lux brands in US market) have flawed naming conventions needing immediate change when compared to the lame MK-mess of Lincoln for example. Even Audi has A's / Q's for cars / SUVs distinction. Agreed, Acura's and Infiniti naming conventions are a mess, not that they are close to top 3 in terms of lux car sales...
That's just my opinion, no big deal, lol.