Ive got a bonnet bra for my car.
I mainly stick it on in the winter but ive recently started using it in the summer to help save my bonnet from flys
Ive not had any problems with it at all with regards to it scratching the paint mainly because im very careful with it, But this is probably due to the fact that i never let my car get dirty enough to have lots of dirt on the bonnet anyway. The scratching is caused by bits of dirt etc getting under the bra then due to the bra vibrating in the wind it causes the dirt to scratch the paint. Also evertime i clean my car the bra comes off and i hoover the inside.
As per the looks to be honest im hit or miss sometimes i like it sometimes i dont
Fitted to my old GT-Sport
Ben