i have a fiat punto 04 model when it rains water collects in the rear footwells. windows all closed etc, had the same problem before with an older model
i had the same problem it was simple to rectify on my 99 punto. remove wipers take off cover to reveal drain holes 2 of them size about 25mm mine were blocked jam packed with leaves etc, problem solved in 20mins and im no mechanic trust me. job done