One of the SEO challenges we face is focussing a website by domain name to the subject area it contains. The interesting case of Clydeside Rentals is that the company rent both trailers and tractor units for commercial hire, as well as holiday home rentals both in Scotland and Florida.
The domain would support both to some extent but it means the website will be fish and fowl. I would normally recommend that each theme is developed as a distinct web entity as it makes more sense to structure information this way – it’s rumoured that categorical distinctions are relevant to large search engine indexing.