Best way to Faro from Cherbourg

Somebody has asked me for the route,i told them Rennes/Nantes/Bordeaux/Irun/Salamanca/Caceres//Merida/Huelva to the pork and cheese border,or go by Villa Formosa to Guarda for the new free fast route to Lisbon,then head south from there,any other ways to go,like Madrid,to Malaga/Algercerias,or that is longer,they are going in a car,and have no hurry to get there.
Told them to check out the Dune de Pyla at Arachon,Mont St.Micheal,and Salamanca,has the oldest university in europe.