I'm looking to put some speakers in my doors, and want something which will blend into the black door panel.

Lots of the speakers nowadays seem to look like something off an alien spaceship, does anyone make a 6" speaker with a really subtle, low profile grille on it?

Yeah, I have seen a few at SuperCheap Auto.
Unfortunately, Fusion are your best options when wanting low profile grills.

Unlike JVC and Kenwood (who really do produce grills that look like they're from space), Fusion ones are very low profile and don't feature any "extra bits".

German maestro, not really a low profile but plain black.
Latest series of the alpine type 's' splits have a nice plain black grill.

I think you can still buy plain genaric grilles from Jaycar or in their cataloge.

In the doors? why not use the inserts in the front?

Hi, there's no room in the front, so it will have to be doors.

Thanks for the tips, I'll check them out.