So after refreshing myself with Mike's guide, my gut feeling is that attempting a roof-box repair in a hotel car park is probably unwise... The risk of something going wrong is too great, especially when you're messing about with torsion bars!
I would be grateful if someone could help me check my roof-box to make sure it's actually fit for purpose. The roof seals are not in the best condition and could probably do with replacing too - is this an easy job?