I usually waxoyl and underseal my cars myself but recently did a search as to where I could take the car to have the treatment done professionally. Dinitrol seem to have an approved nationwide service centres and my local one would be in Doncaster – which I have noted here for future ref.
During the past 70 years DINITROL® have perfected vehicle corrosion protection applications, due to the extreme winter weather conditions in scandinavian countries rustproofing is an essential service.
https://www.dinitroldirect.com/
My local centre is JR Classics at …… http://www.jrclassics.co.uk/
MG ZT info mods and maintenance 