Just had my door speakers repaired. I had a shop install Infinity Reference 6030cs a couple of years back and recently both door speakers began cracking then quit altogether. Took it to a place who does much better work and found that the original installer used some very cheap speaker wire that completely corroded at the crossovers on both doors. Cleaned up the crossovers and replaced with premium speaker wire and they sound better then they ever have...
Before the repair, I thought maybe the speakers would need replacing. In my searching I found that the 6030cs components are no longer manufactured. They have been replaced with the Infinity Primus 6500cs. Although Crutchfield says these fit, from the look of the speaker basket you may have to do some mods with the OEM frame basket. These seem to have gotten very high ratings!
Infinity Primus PR6500cs 6-1/2" component speaker system also fit 6-3/4" openings at Crutchfield.com