rusty sills

[scoots66]

I've an '03 Nevada 1.8 and have rust coming through (badly) on both sills (just infront of the rear wheels). This i see appears to be quite common and I'm having both replaced and sprayed for a decent £300. The garage have suggested they drill a few small holes out of sight underneath and fit rubber bungs so i can let any further water out.
My question is, how do i stop water/rain/damp from getting down there in the first place? Does it travel down the seat belt housing? Is there a cure ?
thanks...x

[paulmurr]

Water is supposed to get into the sills and comes out through the drain holes that Mazda have already made for you. You'll just need to keep an eye on them and make sure that they don't get blocked.

[scoots66]

oh !!! cheers, ive looked underneath and didn't see anything too obvious.. will have another look later (altho it's too late now!)
cheers...