Making all your cars look the same due to the cult of "design language" nearly killed Acura. The Acura Beak is a future MBA business case study (along with the Tropicana container fiasco) in why listening to your customers and focus groups is key. Customers did not like the Acura Beak, yet Acura stubbornly stuck with it and have been marginalized for their hubris. Worse, they forced it onto every car and SUV they made- so there was no diversification of design risk.
Mazda ran into the same problem with what I call "derpy" face. Some overpaid paid Mazda exec thought it made the formerly handsome models like the Miata "happier". It didn't. It made them look worse. The new design language fixes much of the derp face disaster (trademark pending), but again is being forced on EVERY model. The Mazda 3 doesn't need to look like the CX9.
And Infiniti (they still make cars, not just sponsor Red Bull Racing-honest), took this obsession to the next level- also renaming all their cars to start with "Q". Now they can all look and sound the same- so yay?!?
Yes, you in the back? What about Zee Germans? They more seem to incorporate design elements and themes across the lines (see BMW for example) while finding a way to make the individual models seem distinctive. Hyundai/Kia also seem to do a good job of mixing certain design themes across models without ending up with a bunch of different sized nearly exact copies.
There is still time to stop the madness before you get Acura-ized Lexus. You have designers- let them loose!