Peugeot 306 1.9 td meridian

Description:

I have a silver 306 1.9 td meridian model. It has 6 months m.o.t and tax runs out end of next month, but that shouldn't be an issue due to the new tax law due to come in..... It has half leather interior and good tires all round on a nice set of Peugeot alloys....
there is a hissing sound coming from inside the car but goes when you use the brakes but the brakes work fine all round so don't know what the problem i