For me, this raises a number of issues.
I know the Kantian imperative does not say this, but I have encountered many "Buddhists" who try to universalise in reverse. The kind of rationalisation where someone says to themselves, the car is empty, the self is empty, so they won't mind us borrowing their car... oops I dented it and now they are angry at me, look how attached they are to their material things!
Equally with other people's bad behaviour, where "Buddhists" use their own values to judge. Say for example someone else is running around killing insects and I try to convince them to stop on the basis of a viewpoint that they clearly don't share. It leads to conflict with them and can disturb my own equipoise. Both of these examples show the perils of trying to (reverse) generalise to other (non-Buddhists).
On a more serious, properly Kantian, note. In order to treat others in the way I would like to be treated - don't I have to take an imaginary third person perspective on the situation?
It seems to me that Kantian morality is based upon a consensus of vaules, viewed from outside of any one individual, rather than based upon my relationship with my own karma. Living in a society of many non-Buddhists with different motivation and values (and even if they were all Buddhists, no doubt they would all be at different levels of realisation), I think this would make it very difficult.
I'm finding it hard to see a way of applying it in one direction only, treating others as I would like, because once you take that 3rd person viewpoint and start to universalise, it seems very difficult to not start lecturing others on the basis of how you would act yourself in any given situation.
The reason stealing is bad for Kant is because I cherish my own posessions - I wouldn't want anyone to take my stuff - therefore I should apply that respect to their possessions also.
The reason stealing is bad for a Buddhist is because it shows attachment to worldly goods, it reveals that I have failed to see the emptiness of phenomena, and so creates karma.
When I try to combine the two, I end up with some really warped logic - phenomena are empty, I don't mind who takes my stuff, therefore other people's claim to private property is based upon attachment. In fact I am doing them a "karmic" favour by giving all their stuff to charity! (It might sound crazy, but I am speaking from experience here!)