Could be a stupid question. But I'm super curious
 

So I totalled my 03 regal a few days back and i just got a Lucerne and I was wondering could I find a way to put the door speakers in the Lucerne The Lucerne speakers are almost burned out. And I have multible free aftermarket speakers from my last car Is there a way I can make them fit or no I dodont know the demention difference either so just looking for some insight

As service people we had it drilled into our heads, "The only Stupid question is the one that isn't asked ".
There are dimensions that we need to know ,for instance the measurements of the present speakers that are shot and the dimensions of the anticipated replacement speakers. Probably the only way will be to remove one of the damaged speakers and check.