Hmm... the windscreen in the first of those last three renders appears to be reflecting the terrain, in spite of the angle. Sounds like weird geometry, perhaps related to polygon smoothing. 

I've seen this sort of thing before. I once had a perfectly flat table top (a freebie) producing angled and contorted reflections, even with smoothing turned off for the table. The only way I could fix my render was by laying a square prop immediately above the table surface with the same material.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)