Bursting through the web.

On a desert trip, driving south from Flagstaff we drove through a "web" across the freeway.  Exceedingly strange stuff.
We had noticed strange cloud formations and lightening earlier in the evening travelling on I40 from California toward Flagstaff as if a storm was pacing us but never quite hit.  As we were a few miles south on I17, right before the Sedona exit we suddnely saw a "fog" across the road. There was no other traffic and I braked to slow up when suddenly we burst through to the other side.  There was a sticky film on the windshield and car.  When we reached our destination a couple of hours south we checked the car and there was a residue. Being late, we decided to check the car out in the morning light.  It rained that night and nothing was left on the car next day.  It still ranks as one of the strangest experiences I have ever had.
Date is approximate.  PD