An adjustable sofa-bed assembly for use within a vehicle such as a van or RV. The sofa-bed includes a seat portion, a back portion, and either a permanently fixed base or a removable leg portion which allows the legs to be installed into the vehicle prior to installing the seat and back portions to allow for additional elements to be installed beneath the sofa-bed, such as power elements for a powered sofa-bed assembly or for other equipment. The sofa-bed can be transformed from a sofa configuration with an upright back portion to a bed configuration with a laid-flat back portion. When in the bed configuration, the seat portion and back portion are aligned such that there is no gap between the two portions and the two portions lie completely flat, forming a complete bed assembly.