Tub

The Tub is a large white limosine, with a hottub in the back and bullhorns on the front, it is driven by the Gauchos. It is unlocked by beating the suicide bomber side activity in Lava Falls

Insperation
It is based on a 1970s lincoln continental limousine, it's name references it's "Road Boat" origins and the fact that it does have a hot tub in the back.

Usefullness
It is slow, and can be hard to turn do to it's length, but it's high health makes it very useful in missions throughout the game, though it is a poor choice for racing or anything else.