Years ago I use to run MXV4 tires on all 4 wheels, until I got a set with way too much silicon in the rubber, darn thing had terrible traction in the rain. They were so bad in the rain that I had get a set of something else. Shortly after that my sister and her husband bought a new Crown-Vic that came with MXV4 on all 4. I told them about how bad they were in the rain and when they tried to stop and slid all the way through an intersection in the rain, they decided they had to get rid of them and put something else on.
A few years later someone who knew about the bad series of MXV4 tires commented that was only one specific series of the MXV4.
Anyhow that was enough years ago that by now Michelin probably has that problem taken care of, still in all, those bad tires were so bad that I would be very cautious with any MXV4 tires until I had actually done a test stop in the rain.