My original post has somehow disappeared, dunno why.
My Q: Does anyone have any experience with installing a DELL WWAN 5520 card in a Latitude E6410? I cannot find any information re whether this works or not.
Welcome to the Community. I see that the Latitude was shipped with the Dell Wireless 5540 WWAN card. I have not tried it with a Dell 5520, but you can certainly give it a try. If you want instructions on how to install the card, below is the link.
<ADMIN NOTE: Broken link has been removed from this post by Dell>
Hope this helps.