ITunes 11.1.5 completely wiped ipod 160gb classic

Question

Updated to itunes 11.1.5, unchecked a few songs for my ipod 160gb then hit sync.  The whole ipod has been wiped!!!! 
I spent hours with all this music and playlists, now totally gone, so much for new music on the roadtrip tomorrow.  To say I'm hugely annoyed would be an understatement.
To top it all off I've had to restore (think ipod wouldn't recognize?) which has resulted in the error 'the ipod could not be restored because it is busy.

Answer 1

The 160GB iPod classic was released in 2009.  It is still being sold unchanged.  That's a much longer product life than most Apple products.  So, a 160GB iPod classic can be brand new, or almost 5 years old.  A high percentage of them currently in use are approaching the end of their useful life (even if treated carefully), because hard drives eventually wear out and become unreliable over time.  They are fragile and have many moving parts.  It's not a matter of IF they start to have problems, but WHEN they start to have problems, just like hard drives in desktop and laptop computers.
Here's an example of what often happens...  An aging iPod seems to be working fine, but the hard drive is slowly becoming less reliable, with problems like bad sectors.  As long as data updates are small, incremental, and not that frequent, it continues to work fine, with minor issues such as occasional slowness and songs that skip.  The owner wants to give it a "fresh start" by doing a Restore.  The Restore requires a major update to the hard drive's data, and the hard drive errors out, "bricking" the iPod.  Conclusion by the owner...  iTunes broke my iPod.  It can't be a coincidence that the iPod's hard drive "completely died" exactly when I did the Restore.  iTunes is bad.
No, it's not a coincidence, because the hard drive was already unreliable.  It continued to work as long as most of its data stayed mostly static and unchanged.  But when a major update to the hard drive's data took place, such as the Restore, it failed.  The Restore revealed the problem, it did not cause the problem.
There is no problem that is specific to the latest iTunes and 160GB iPod classic.  The problem is that many 160GB iPod classics in use today are aging, and their hard drives are becoming unreliable.  In your case, your iPod's hard drive may be unreliable because of the "hot car for a month."  When you had the iPod set for Manually manage music, and mistakenly changed it to using syncing, that was a major change in the hard drive's data (like doing a Restore).  That may be why iTunes then indicated the iPod was corrupted.  That sequence of events is not related to using iTunes 11.1.5.