Mine was 1 Inch too narrow. So I widened it with two Aluminium box sections down each size. Total weight including Twizy 600KG, so no need to be braked. Mine has done a few thousand miles now.
The Twizy is balanced over the central axle which is why there is a big gap at the front. I can load it solo but easier to have someone watch you on. There are blocks which I drive the wheels upto. You can just see two axle stands under the rear end to stop it tipping up when driving the Twizy on or off when not connected to a tow vehicle. These where easier and more flexible than adding legs.