1999 Mk4 / 6n Polo Brake Lights

Morning gents,

My girls's just passed her test so is tootling round in her Polo now, the only thing is a bit of a dodgy passenger side brake light. The damn thing doesn't work, until you give the cluster a bit of a slap, it works, then a second later, it will be out again. Frustrating!

I took the bulb and holder out over the weekend and gave it a load of WD40 as well as the multiplug on the bulb holder, both done no good!

Are there any common issues I should be looking for on the mk4? I've had to silicone around the driver's side cluster as it was letting water in and shorted the central locking pump - I wonder if this side has a similar issue.....

On the subject of brakes, does anyone know why my girl's 99 Mk4 1.4CL wouldn't have a high-level brake light? I've seen poverty spec 1.0Ls with them and I think it's strange her's doesn't. Wonder what they are like to fit....?

Thanks for any help fellas.