My first speaker upgrade will be getting rid or the crappy outside speakers. I just ordered some Polyplanar MA905W
They are relatively flush mounted and require only a minimum of depth for mounting. It should mount within the thickness of the wall without going all the way through to the inside. If it needs it, I can fabricate some nice looking shims to raise the speaker a bit away from the wall, but the shim won't have to be more than a 1/4".
FAA A&P mechanic, ex-RV dealer parts dept
Retired B-52 Gunner/Flight Examiner, B-52 Crew Chief
2016 Jayco Eagle HT 29.5 FBDS w/ 15,000 BTU AC, 50 amp service, upgraded counter top, thermal pane windows, elec. stab jacks, outside grill, backup camera and MORryde pin box.
2011 GMC 2500HD DURAMAX/ ALLISON