I don't know how much of a breach you have with those cracks, but for now, duct tape the damaged portions until you can get a replacement.
Enough moisture (i.e. driving rain at highway speeds perhaps?) will cause all sorts of running problems. I believe there is a current thread in this forum on just such an incident...
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car