Great video thanks for the link , just had mine done but pleased to say it was not as bad as that car, thats the worst ive seen around the scuttle and inner wings.
I've watched many of his detailing posts in the past, his knowledge on the subject is very good. With the rust he's seen on his car I'm very pleased that mine has seen practically no rain and definitely no salty roads in the 12 years I've had mine, though I've not removed my wings so who knows what lurks within! From reading many previous threads it appears that rust behind the wings is very common even if it's not externally apparent.