First and foremost it is a saloon. There are no two ways about that one.
It needs to be large (S class Mercedes kind of size), but not Maybach large.
Not really bothered about cost, just want to know if it exists.
It has 3 full size seats in the rear (like a Hummer would). No sub standard middle seat.
The seats need to be wide enough for 3 six foot, 16 stone men to sit without being squashed into each other. Additionally all 3 seats must have headrests, and seat heating with 3 point seatbelts. There must be no hump in the floor for the back middle passenger.
The centre console between the driver and front passenger should contain a fridge (like a landrover discover).
The trunk should be deep and very spacious, big enough to carry a person, plus luggage for 6.
Finally the car should have a certain amount of driver appeal. I don't expect sports car handling, but it should be more of a sports limo (BMW 7/ Audi A8) than a limo limo (Phaeton, Rolls Phantom).