Does anyone know if the F90BT is compatible with SDHC cards or is it only compatible with SD?

Please verify if anyone has tried using an SDHC card.

SDHC card is anything 4GB or bigger, yes they work with 4gb and bigger sizes.

Gotcha. Thanks.

Please forgive my ignorance of card types. Is there any significance to the class? While shopping, I've seen class 2, 4 , 6, and probably others. Will nay work on the F90BT? All the manual says is SD cards with an 8gb max.

Class refers to transfer speed, so theoretically higher class cards will work faster (at least when loading them on your PC... AVIC may not be fast enough to see the difference)...