We have different cab covers and use the one that fits our needs.
1) Warm weather - A woven cloth that hangs from suction cups on the windshield and side windows. It provides privacy and limits sunlight. We had it made at a flea market a decade ago.
2a) Cool weather - Reflectix on the inside of the windshield and side windows. I cut Reflextix to fit the windows. I painted one side white and the inside tan to match.
2b) Cold weather - The vinyl wraparound that LD supplies with new rigs.
2c) Really cold weather below 35 - we combine 2a and 2b.
3) For quick privacy in a one-night stop we use the LD installed curtains.