Thanks for all the replies. Got some temp gauges setup and yesterday i saw around a 7 degree difference. At 1:30pm the trailer temp was 78F and cabinet was 85F. The sun passes over and shines on the other side of the trailer. Moved the cabinet temp gauge to that side and saw 89F in that cabinet at 7pm. Wasnt even a super hot day yet.
Think i want to go for the wine cellar approach versus venting because of the dusty conditions here. Im hoping the cabinets can remain in the center of the hot and cold spikes. Instead of the cabinets getting hotter than the trailer itself.