Swhale aka The FPS Creator,
Innovative thinking
If you dont want to wait for future in built vehicle support and have the time to experiment then go for it.
If you have the time I am sure it would be an experiment well worth the effort - from a learning point of view.
With enough level design effort you could possibly find situations in the current 40 x 40 tile area to make use of a short vehicle ride as it were possibly including some cirular movement, up ramps and back down somewhere else perhaps to give an extended feel to the time spent driving.
If you can do things to achieve an apparent bigger map area by extending the appearance of the horizon in game then the size of the level could at least be visually enhanced.