Hyundai Getz, problem with water-thightenss

My friend bought Hyundai Getz in 2003 in Croatia, and he has a serious problem when it rains, usually floors and carpets on driver's and
co-driver's seats are wet.
The thing is that he is parked on a slight incline and this is the only way to reproduce it when he was in service center.
He already visited service center about 10 times and every time they tried something else with no success.
Now his patience is near end, and of course no one from official Hyundai contact on their web pages responds on e-mails.
Anybody had a similar problem ?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.