Today, I fixed the leaks on my Fiat Tipo 2019. I had to remove the rear lights and bumper to identify the issue. The leaks were definitely coming from the rear air vents on both sides below the taillights. I used Granville Clear Silicone Sealant (automotive), which I bought from Halfords for £5.29. I also sealed the plastic rubber covers on the sides of the rear taillights because water was going under the rubber instead of passing through it. That’s how water was getting to the vents and taillights. Apparently this is common problem with fiat tipo 2nd generations.
The entire process took me 4 hours,
It’s not hard job, easy to do, but it requires patience.