Thanks again to this forum for getting me looking in the right sort of area, finally found and fixed boot leak.
Most of my water ingress occurred when the car was parked up in the rain. Had all the boot carpets out to check the air vents on either side. Both had a loose fit and very obvious the water was coming in round the edge. Ordered 2 new ones from BMW, £11.50 the pair with VAT. Had a look again as something did not seem right, the rubber flaps opened into the boot from the outside. This did not make sense as I think they are to let air out the car (air drawn or blown in front, leaves through rear) also when the doors are closed lets air out.
Had a good look on the net for Z4s with rear bumper off and it turns out mine had been fitted the wrong way round. This of course meant the seal was on inside of car and not outside.
Fitted new ones correct way round and boot totally dry no matter how much water I pour over the body joints and boot channel.
On looking at the old ones I would suggest they have been like that for some time but as far as I can see the rear end is all original so no real reason for someone to remove and refit incorrectly. I therefore guess they had been installed incorrect from new. The previous owner had car from new and stored in his garage, I am guessing he never noticed any leak. Anyway happy now but will leave the carpets out for a week or so just t make 100% sure!
Most of my water ingress occurred when the car was parked up in the rain. Had all the boot carpets out to check the air vents on either side. Both had a loose fit and very obvious the water was coming in round the edge. Ordered 2 new ones from BMW, £11.50 the pair with VAT. Had a look again as something did not seem right, the rubber flaps opened into the boot from the outside. This did not make sense as I think they are to let air out the car (air drawn or blown in front, leaves through rear) also when the doors are closed lets air out.
Had a good look on the net for Z4s with rear bumper off and it turns out mine had been fitted the wrong way round. This of course meant the seal was on inside of car and not outside.
Fitted new ones correct way round and boot totally dry no matter how much water I pour over the body joints and boot channel.
On looking at the old ones I would suggest they have been like that for some time but as far as I can see the rear end is all original so no real reason for someone to remove and refit incorrectly. I therefore guess they had been installed incorrect from new. The previous owner had car from new and stored in his garage, I am guessing he never noticed any leak. Anyway happy now but will leave the carpets out for a week or so just t make 100% sure!
