if the car has a sunroof ...look under the car at the sills basically where you will see the jacking points on these there are drain holes which get crushed and clogged up easily if you take a flat blade screwdriver along the edge of of the these you will see some areas that have a bits that protrude slightly sort of the size of your pinky finger nail ok these are the drain holes ...stick a a thin flat bladed screwdriver up them to open them out and clear them of gunk ....now go to the sunroof open it up and pour some warm water down the drain holes that you can see ....another tip is to run some cycle gear cable down them for as long as you can and waggle it up and down .
after pouring the water sown " soapy water is a good idea " after a moment you should see water coming out the holes in the sills and onto the road .....if not then afraid its seat out carpet up trim panels off and a more through investigation .
let us know h0ow you get on ....ps another tip with the thick cycle wire is to pop it into the holes in the sills and again waggle wiggle it about
cheers
stu
ps
another often over looked one is the door drain holes get clogged up and water builds in the corner near the hinge and can drip out there so also check the drain holes on the doors,its easy enough to whip the door cars off and clean the insides out a wet and dry hoover is always handy .
