Hi Im new to the MX 5 I got it on the Tuesday after easter so still getting to know it.
Its Mk1 Eunos Roadster its a jap import so would have thought that there would have been an after market fog lamp fitted but when I put the fog lamp on and went to check there is a Roadster sign in the boot lid that lights up, must be ok as a fog becouse of the mot.
Thanks
Firstly welcome to the addiction of mx5’s
To answer your question the light on the bootlid is a high level brake light that has been converted into a fog lamp, quite an easy conversion & done on many cars.
Totally legal as falls within the requirements of the mot regulations.
Rear fog lamps are not compulsory in Japan so when imported either have the brake light converted, the offside reverse light converted or an aftermarket fog lamp bolted to the rear valence.
Hope that answers your question.
Drive safe & have fun in your 5…
Hi
I’ve had an import eunos for about 17 years.
My garage told me that the boot lid brake light can’t be used as a fog light because it’s too close to the brake lights!
I’ve been fitting low level after market ones that are really easy to knock of on kerbs etc!
Next time it falls off I’ll convert the boot lid light 
O/S reversing light conversion with a high-intensity red LED bulb is the most sensible IMO - Keeps original looks, retains the third brake light, avoids the dangly Lego brick light - and one reversing light is still plenty.
What’s not to like?
Its the only way to go