Here's my story:

So, I've started to get an intermittent driver's side 2nd row speaker. Sounded very fuzzy at low frequencies. I went to Crutchfield and ordered some component speakers as replacements - Alpine 6-1/2" 4 ohm. The day I went to fit them I removed first door trim (pretty easy) and OEM speaker only to reveal that it was a 6-3/4" 2 ohm! (LR #XQM500290). Needless to say I returned the Alpine speakers to Crutchfield, don't really feel like having the amp drive 4 ohm in a 2 ohm application.

After some fruitless web searching, and an analysis of the removed OEM speaker (which was a Harmon Kardon and a pretty nice design) I decided to buy a replacement speaker from the Land Rover dealer in Pasadena.....it was only $13!!!

Fitted that and it sounds great - end of story.

If anyone needs tips on how to remove the rear door trim, let me know, I'll write up some instructions.