Hi Nigel and welcome to OSM! Thank you so much for helping out! 

I just wanted to point out that the roads in the parking lot should be highway=service not "unclassiefied". 
You can read the details on the Wiki:

https://wiki.openstreetmap.org/wiki/Tag:amenity%3Dparking
https://wiki.openstreetmap.org/wiki/Tag:highway%3Dunclassified