So, to summarise, you invite your girlfriend to a weekend camping in the rain, which requires her to sit on the pillion of a Duc for hundreds of miles in the rain, break down, go home, then
make her do it all over again in a Mini and all she does is take the mick and laugh at it on the way home? Hmm. Sounds to me like you have found a diamond!
Seriously, though, I'm glad you were both able to see the funny side.