Condensation in the trunk???

[Farmlifer]

After a long 55 degree drive today with a few traffic jams (car stayed at normal operating temperature) while emptying the truck when I got back noticed condensation on inner lid above oil/coolant area. After further inspection found more condensation under the plastic cover... Dried everything up just wondering how to prevent this going forward.

New coolant cap needed or something more drastic?

Not wet anywhere on carpet and certainly not a show stopper or should I say “go stopper” but if a quick DIY fix will do.

Thanks Forum!