Indeed. Checker plate is a really bad sign - if you see it on the bottom of doors etc run. Run fast. and Run Far.
I deliberately bought a disco that didnt have a towbar fitted. Yes its going to be an extra job to fit one, but it shows its never been used for towing. One owner from new who has only used low range in the snow. Although i must admit i'm envious of the 18 month old D4 he's replaced it with.
Don't be - it'll be broken more often than not, with all that electronic "stuff" on it, and the electric handbrake !!
The towbar comment is good advise too - they are out there - they can take some finding, but they are out there...