So after researching roofboxes into the ground we have now come full circle and decided to get a trailer. The main reason for our change of heart is ease of use. Weighing the advantages and disadvantages of each as I did here it looked like the roofbox won out on cost, but having thought about it a little more we think that in the long term a trailer would be better. 

It's just far easier to hook up and pack a trailer than to fit and fill a roofbox. Fitting the roofbox, by first getting the roofbars on the roof then lifting the roofbox into place and fitting the U bolts seemed like a really awkward series of manoeuvres which risked damaging the both the car and my back. Once fitted filling the roofbox would be another awkward affair with lots of over-reaching and (as my mum would say) mauling.

So then what about the cost difference? Well in the end the difference was not so great, around £100 which in the long term is not huge. The trailer also offered additional benefits which on reflection will make the trailer option more useful than I had first thought.

Firstly, the towbar allows us to fit a solid rear mounted cycle carrier and lighting board which we are far more likely to use than roof mounted carriers attached to roofbars, for  all the same ease of use reasons.

Secondly, the trailer will be useful for other things, like trips to the tip.

Thirdly, the additional weight is carried by the trailer not the car, which means less wear and tear on the car and less effect on the handling.

Finally, it turns out that the combined height of our car and a roofbox would mean we would have to pay additional charges on a ferry anyway, so there was no advantage to the roofbox in that case.

So then we're going for the trailer, an Erde 102 to be precise as it's the smallest and cheapest, and should fit our needs adequately. At the end of the day the choice between the trailer and the roofbox was a close call, as my sister-in-law says "It's all Swindon roundabouts".