Some cars leave a paper trail; the Lotus 63 left a name and a place in Lotus's list. What follows is what can be said with a source behind it. Colin Chapman / Maurice Philippe drew it.
Where it came from
The Lotus 63 was an experimental Formula One car using four-wheel drive, designed by Colin Chapman and Maurice Philippe for the 1969 season. Chapman's reasoning behind the car was that the 3 litre engines introduced in 1966 would be better served by building a car that could take full advantage of its power while retaining the Lotus 49's simplicity.
In context
Its family tree is legible: it took over from the 49; its successor was the 72. Nearby in the Lotus catalogue sit the Lotus 100T and the Lotus 101.