mercymercedes

I took the headliner panel off my W124 yesterday in order to clean and prepare it for a new DIY headlining. It's been on my mind for a few years as the old one unglued itself and I've been wearing it like a hat every since.

Now this is a german manufactured car that was officially exported to my country, which is semi-tropical and gets temperatures of 37 C during the summer.

Naturally the car is like an oven when left outside all day and I now know why.

There was absolutely NO heat insulating above the headliner (itself is only 3mm thick with a tiny slither of foam sandwiched between two layers of fibre glass) and I ask why is there no heat deflecting material in the ample space above.

I this normal or has my car been bodged in the past? Is there some technical reason why mercedes didn't put panels up here and does anyone have an opinion as the whether heat reflecting/absorbing are a good idea to fit. I'm nosing around looking for suitable (cheap) material that can fit in the space and worried that filling this space with unsuitable material might cause the steel roof to buckle or the paint to overheat and flake.

Any advice very welcome. Thanks.