Those "Tow Eyes" are only to be used for the loading and unloading of the vehicle onto a flatbed tow truck. They are not to be used to secure the vehicle to the bed. Although I do not have my ForTwo yet (is is in transit right now) I expect you will find some small oval holes (about 5/8" wide and 1-1/4" long) in the underside of the chassis. These are called "T-Slots" and are designed to allow a T-Shaped hook to slip inside, then turn sideways and secure the vehicle.
Do not use the Tow Eye except for horizontal loading and unloading, as it is designed to be pulled in a striaght line forward and not down.
I currently manage a fleet of 12 tow trucks and know of what I speak!
Jim