Simpler approach

Vehicle.kt

class Vehicle(var type: VehicleType = CYCLE) {

    @Deprecated("Use constructor with 'type' info instead")
    constructor (isCar: Boolean) : this(if (isCar) CAR else CYCLE)

    @Deprecated("Use 'type', instead", ReplaceWith("type"))
    var isCar: Boolean = false
        get() = type == CAR
        set(value) {
            field = value
            type = if (value) CAR else CYCLE
        }

    enum class VehicleType {
        CYCLE, CAR, TRUCK, SHIP
    }
}