I mean, these machines, Stuxnet is a Windows virus.

Nimda (2001), named Concept Virus by its author, one of the first multi-vector Windows viruses.

I remember Windows viruses existing for Windows software that only existed in beta-format and available to developers.

As well, the first released models came with a Windows virus.

How can a Windows virus end up on an iPod?

A Windows Phone 7 antivirus could be scanning for Windows viruses.

And with a few exceptions individual Windows viruses aren't terribly widespread, just the sheer number of different ones makes infections common across the board.

So most Mac AV software spends 99% of its time scanning files for Windows viruses.

And no, the Intel chip does not make a Mac vulnerable to Windows viruses.

The company has managed to ship a limited number of GPS devices for cars containing not one but two Windows viruses.