A highly liberal person (a democrat) who lives an upper-class (republican) lifestyle enabled by wealth. Holds philosophically correct liberal positions that they couldn't hold if they weren't so well protected and insulated (through their wealth and power) from the side-effects of those positions. Some common issues include: homeless rights, non-native species removal, etc.
Some Limosine Liberals are thoroughly conservative but publically liberal only in certain areas that are safe for them-- a classic example being: supporting arts organizations that present controversial art.
See: most local politicians in San Francisco, Berkeley, and Marin counties, California
Of course Holten thinks that new City housing shouldn't have parking requirements because cars are environmentally incorrect-- he's a Limosine Liberal who takes cabs everywhere.