Hi all, I know I've come late to this but in case anyone else is looking for a bolthole on their way home.
In Zuera, which is near Zaragoza, I've stayed a couple of times in Las Galias.
It's one of the cheapest in booking.com and right by the motorway.
A bit old fashioned in parts, but clean and has a new addition to it, you can come in late too.
However, I've only stayed with a car so don't know about internal parking. Outside they have covered parking coorugated steel sheet-type.
It tends to be used by workers moving about the country who I've never had any problems with.