I had the same problem with a Daewoo Nubira a few years ago.
When it rained water dripped under the passenger glovebox since Autoglass replaced a cracked windscreen. I put masking tape around the seal and used a hose. No leaks. Went back to autoglass twice and they tested and said it was not the window seal. I then started checking wiring looms etc but eventually gave up and traded in (a shame as it was a nice car which was basically a better looking Vauxhall).
I did think about using a coloured fluid for tracing the leak but could not think of a solution that would not stain.
ex daewoo owner
May 2006