Worth a try, my MX5 has very slow seatbelt retraction. Ordered some and I’ll see how it works.
I am curious what your experiences will be!
Has made an improvement, not perfect but acceptable. It’ll be interesting to see if the improvement lasts.
At my 4/4 the improvement lasts since 6 month.
Of course I fold the "easy up" away from the belt as far as possible and I make sure that no bag or clothes are in contact with the belt.
I think that the spray reduces the resistance of the belt when it rolles up, so that the weak spring is compensated somewhat.
As I mentioned the function -on my car- is now
"not perfect but much better so I don´t intend anymore to remove the seat belts.