It was 31 degrees C here in Leeds today.
Just noticed daughter's Citroen AX parked facing south, on our north facing drive (hence in the shade of the house) has developed a diffused melt/burn mark on the rear bumper about 12" x 1". The plastic has definitely softened and flowed and is burnt brown.
We have builders working in the house who parked their large white van facing north behind the AX but it was parked with the back doors open all day so couldn't have been closer than 5' or so, so presumably we can rule out hot exhaust fumes, and it's not as if they'd been sitting in it with the heater on.
Only thing I can think of is that something must have reflected or focussed the sun's rays onto the bumper, but what? The van's rear view mirror on the driver's door by any chance, which would have been in full sun?
Anybnody seen this before?
DG