Toyota Aygo Red Roof Fading

[neilf]

Mum has a 4 year old Aygo as per the pic. The red on the sills and rear bumper are plastic. The front bumper and roof are vinyl wrap. In short, the vinyl on the roof has slowly turned pink. Car still under warranty so she enquired about having it replaced. Dealer pulled a face and blamed her cleaning products... until she pointed out the vinyl on the front bumper is still glossy red! They’ve removed a small piece of vinyl and sent it away for ‘testing’. That was a month ago, heard nothing since.

Anyone have any experience of similar? I spotted another Aygo this week with the same roof fading. Wondering if it’s common.