No direct experience but there are lots of companies.
Some names below, but you can google Malpensa NCC, or Milano NCC, or Malpensa airport transfer, and lots of companies will pop up. NCC stands for Noleggio Con Conducente (Car Hire with Driver), which is a highly regulated category of licensed drivers in Italy. I'm pretty sure they'll all be able to get you there in one piece. Get some quotations and see who has the best prices. It's probably around 150euro.
http://www.malpensancc.it/
http://www.noleggio-conducente-milano.it/
http://www.mynccmilano.it/tariffe.html