Yeap, the lot. The circuitry inside needs changing cause a small bit has melted and causes the passenger and driver courtesy light to stay on permanentely. The only way is to remove the 2 bulbs or change the whole unit as mercedes do not change the circuit only. The car is for sale so has to be fixed.
if you are selling the car I'd take the circuit board to an electrical engineer or radio specialist and see if they can manage a repair. If it's obvious what is wrong PCBs can very often be repaired if you know what you are doing.
I got the light unit repaired and reimbursed by my warranty. Thanks for that, total amount was £490.
The car is def going this saturday so if anyone out there is interested and has £10K in his pocket.......