I was looking for an adhesive to attach foil-backed insulation panels to the walls and roof of the van. This seems to meet the requirements:

• Stays flexible when set to accomodate vibration and warping of the van body
• Can fill the gap caused by the curved walls of the van (unlike thin contact adhesives like 3M 90 spray)
• Sticks to painted metal and the lacquered foil of insulation boards
• Resists temperatures up to 90ºC
• High tack (unlike some other silicone sealants which otherwise have good void filling and flexibility properties)
• Plus, it’s low odour and solvent-free

Buy it in the UK: £6 from Screwfix.com