mx5cartalk.com

Simply work from cheapest solution to most expensive.

I would assume there would be an inspection hatch either in the wheel well, or maybe under the front bumper.
If not, removing the plastic tray from under the bumper should allow you to get to the back of the lights.

Once you can get to the backs, you should be able to see what the issue is. (change bulbs, check the wires arent loose, etc)

I would most certainly suggest that the bulbs have blown.
Especially if it's cracked, which suggests one has been hit with something.

Why not just take it to the auto electrician and send the bill over? Why hassle so much if you aren't paying for it?

You need to pull the front of the inner guards to access the rear of the light and wiring.
About 6 plastic rivets and a couple of screws on either side.
Removing the wheel helps.

I'm guessing you figured they only work with the light switch in parkers or headlights then the dash switch.
There are a couple of different types and are not cheap.
Here and Here and Here

When you get the broken one replace, recommend make a pair of headlight protector's from some motorcycle headlight film (from supercrap)

IMHO they are/were useless.
I replaced mine with covers from the US poverty Pack (thanks reggie)