Whether you're specifically into auto design or not, if you aren't already following them you should definitely check out GM Design Center's Instagram. The company has steadily been posting everything from interior and exterior renderings to CMF studies, cabin mockups, clay models and archival images going all the way back to the 1930s. I think they've really nailed the mix of futuristic, current-day and retro.
On that latter note, I found the images in this post particularly eye-catching:
There's a short write-up on Loczi, as well as another 46 of his older renderings, up on Dean's Garage.