Next year I'll be retiring and I've always wanted to hire a motorhome and tour Europe, I want to hire one in Spain (I'm from Gibraltar) spend about a month touring and then drop off back in Spain, could you recommend any good hire company's.
I’m sure that others will join me in saying that a month is not long to tour Europe! You could easily spend that in a couple of French Departments.
Try and narrow down an area you particularly want to explore. It’s not much fun driving everyday.
Sorry I don't know anything about hiring motorhomes, having owned one for decades.
There's a temptation to look at the map and notice the big towns and cities, but these can be more easily visited later, by train or fly/drive. A motorhome is no advantage in London, Paris or Berlin, especially if it's hired.
To take advantage of a limited time in a hired motorhome, I would look to your special interests and build the trip round that. Nature reserves, national parks, castles, steam trains, archaeology, mountains, forests and lakes - places easier to visit in a motorhome than from a city hotel.