I was wondering whether there is any legislation to force manufacturers to build cars that allow the 'ordinary' motorist to change a light bulb.

I have just bought a 2007 Vauxhall Vectra and when I returned to it one evening I was informed via the warning system that I had a faulty offside front light.
As I had purchased the 'recommended' set of bulbs, I popped open the bonnet - then shut it again, went to the glove box, pulled out the owner's handbook and soon discovered that I needed to take the car to a Vauxhall workshop. Aside from leaving the car parked overnight in a dodgy part of London, I had no option other than driving home – illegally.

Next day, I took the car to my local Vauxhall dealership and several hours and £52 later I had a fully functioning set of lights!

I have written to Vauxhall several times to no avail. Oh, I get a reply alright, but not one admitting that this 'design' is not fit for purpose, e.g. the necessity to be able to change a headlamp bulb by the roadside! And, no surprise here, they won't be helping me towards the cost incurred, giving the reason that the bulbs are wear and tear items.