I drive a VW Polo TDi 1.4 and I realised that both my main brake lights were not working at all, however, the brake light at the top of my boot is working perfectly. As far as i can see no fuses are damaged and shortly after checking all the fuses the glow plug warning light started flashing while driving. Can anyone shed any light on this issue? Is it serious or are they related? Any help would be much apprectiated.