Water leaking into passenger footwell

[Stephen Skeggs]

Ok well mine only leaking on the drivers side so what would I have to seal under the scuttle panel I'll be sticking it in the garage after work tommoro and having a look

 

[spidey23972]

I have just purchased a 13 plate Altea XL, when I test drove it last week I noticed like a mildew on the seat belts, and today, the day I purchased the car, I noticed that part of the metal of the passenger seat adjuster is really rusted, it's to the right low down near the handbrake, could water leaks gave caused this?