There is one on my Plus8, fitted by a previous owner. Moto Lita. It locks in position with two sprung lugs and has a built in lock in the boss that uses a key. No need to carry the wheel with you then!
The key is like those used for the old Krooklocks etc.
The only time I remove the wheel is for easier access to the dash for removal. It is easy enought to get in/out of the car so no need to remove. If getting in and out is an issue then get a removable wheel. It is no problem to remove/refit.
As it was on the car when bought I can't comment about distance of the wheel but I am happy with the fit.
