Been there way too often myself.
Hate to say it, but you are marked now. They will be back soon for the replacement unit. Our trucks stand out and are remembered. Thats why they went so far to break into yours.
I haven't had a radio in mine for almost 2 years now since it was stolen.
I put part of the blame on radio mfg's. Any new car today comes with a radio that needs a code to operate if powered down. Its impossible to buy such a feature in an aftermarket radio because they thrive on replacement sales.
Unfortunatly its illegal to hollow out a radio and fill it with TNT and rusty scraps. Leave the door unlocked. Problems solved one at a time. Repete as often as necessary.
John C.