Many thanks for all your thoughts. To answer the odd question (MUCK ADAM)the Cair o Port I have is described as 2m x4.4m (small). This was just enough for an Aero but more than that fitted inside the garage with access to cupboard space still available. With door access at both sides of the chamber the snug fit presents no problem. I had storage fitted all around the garage reducing the internal space so was confined. I phoned the company (Hamilton Classics)and discussed my plans and was given some helpful information. The design of the roof has a slope which gives clearance to up and over doors, this was a plus point for me. I was also told they had incorporated a 3rd fan at some stage in their history to help reduce moisture in hard to get areas like the engine bay, another plus point.
(DAVE W) Yes, Dave, I could get my money back with a cheap camping holiday, although it did take 2 hours to assemble.
(FINGLES) I am encouraged in the knowledge that the company has been running for so long and that you have had 13 years of use with no issues.
(SPANNER JUGGLER) Many thanks for the tip reference the fans, they do look straighforward but clearly effective.
(ROADSTER BOY/GAMBULUNGA) For about 4 years prior to the Aero I had a Roadster and 4/4 in garage but had no starting issues. This S1 Aero just seems more sensitive to the damp than the rest of the Morgan range. Didn't try a dehumidifier, wasn't sure how airtight my garage was