This is a Summer Car.
If used during a Summer Event, you get 25% extra cash and XP from races (50% before the 2018 Surf n' Turf Event).
The Six Four Plus Three is a car that could be obtained either by completing the Add That Up achievement, which required using 2,000 nitros with a summer car during the 2015 and 2016 Summer Events, or from the dealership during the 2016 Summer Event.
- Towards the end of the 2016 Summer Event, it was also made available via the dealership. Its price was increased from $1,500,000 to $20,000,000.
- This car is the only car to feature more than one person inside it.
- This is the only summer car in the 2016 Summer Event besides the Summer Classic to not be a water vessel.
- This car is the most expensive car to be purchasable.
- It resembles a 1964 Chevrolet Impala, which is colloquially referred to as a "six four."