How many vehicles does a man need to be completely satisfied?
One for traveling overland. A motorboat would be useful to quarter the sea. A snowplane would not be redundant for traveling to a snowy wood. And, finally, there are places devoid of roads, for instance, marshes where an air-cushioned vehicle would be suitable. Expensive, isn't it?
Let us check into this matter. The automobile itself has many of the properties needed by each of the above vehicles: an engine, a cabin. Then why buy these things four times?

The inventor from Russia proposed to use a set of modules with an automobile as a power base.
The case with a snowplane is quite clear. Skis are attached to the wheels and a frame with an airscrew is attached at the rear part of the body. The airscrew is driven by the power take-off shaft. A comfortable heated snowplane with a 100-kWt engine is produced.

For a motorboat, it is necessary to purchase a body with a screw-propeller and a rudder. An automobile carries the motorboat body to the water, then the body is set afloat and the automobile embarks it. The rear wheels are fixed, the front ones are connected with the motorboat rudder, and the power take-off is connected with the screw-propeller.

An air-cushioned vehicle is produced in the same way: a platform, circular shell, lift rotor, and cruising screw. The automobile is placed above. Now you can fly at a small height and need no paths or roads.