Any reason for this happening . . . . . .?

[Arnold_Lane]

Just had 10 days abroad and left car at long stay car park at Gatwick.

On return, the stereo (standard) says that it can't read the SD card with my music on it.
Took it out and put it in to the computer and it says it needs to be formatted.
It was working fine on the drive down to Gatwick.

Any ideas why this should happen? Should I remove it from the slot in future if it is going to be left for a while?

[monsta]

Cheap card? 

[gtiaps]

Could be the card is corrupted iv had it with my phone a few times always decent cards Scandisk Samsung and Kingston not sure what the problem is been just had to replace the cards 

[Arnold_Lane]

Cheap card?

Could be, but just surprised that it 'went' during a 10 day lay up, when it had worked perfectly the evening before.

[Finglonga]

A card can get corrupted any time without warning. Format it, lob all your music back on and hopefully it will last.

[rjwojcik]

Does it work on your PC?  Might just need reseated before you start formatting it?