The SOL Poncho is a simple poncho without buttons, shock cord or tie-outs. But it is large and made of the same material that makes all of SOL's products so unlike Mylar alone it may rip or puncture but it won't tear endlessly like Mylar alone and it can be repaired with tape or duct tape. It also has the same heat reflective properties of SOL's other products. And it is compact.
The closest Poncho might be the Sea To Summit Ultra-Sil, however, it has all the bells and whistles that the SOL does not and it comes at a price. The Ultra-Sil costs $100 and the SOL under $10 and is less than half the size.
I have never needed a Bug Out Bag (BOB) in my car but if I did then this would be a welcome component.