Best route Calais to Valencia? (and scrapping car in spain?)

My (spanish) wife and I are moving to Spain in October. We are going to be driving down and have narrowed it down to 1 of 2 possible routes. Either:

Calais > Reims > Lyons > Montepellier > Barcelona > Valencia
or
Calais > Paris > Orleans > Bourges > Clermont-Ferrand > Perpignan > Barcelona > Valencia

Both seem to be roughly the same distance, roughly the same toll costs and take roughly the same amount of time (according to all the various route planners).

Does anyone have experience of these routes or can recommend one over the other? We're not looking to site-see on the journey, so really just want the quickest and easiest route.

Second question...

Does anyone have any experience of scrapping a UK registered car in Spain? We're driving our car down - it's a 12 year old rover, so worth virtually nothing, but is in very good condition (only 67,000 on the clock) and should be more than fine for the journey. We only plan to use it for a couple of months whilst we sort out residency etc and sort out buying a new car in Spain.

I've read a lot about the new rules affecting Uk registered cars but can't find out anything about exchanging/scrapping a UK registered car. Would a Spanish car dealer consider accepting a UK registered car as a part-exchange or would there be any problems scrapping the car with a Spanish Scrapyard as it would still be UK registered?

Many thanks....