Heating Warning
WARNING: This page is about a different car, the 2016 Volkswagen Beetle, 2015 Volkswagen Beetle, 2014 Volkswagen Beetle, and 2013 Volkswagen Beetle. However, it is still accessible from the selected car via links, so may be relevant.
Do not heat with a naked flame under any circumstances. Localized overheating can cause structural changes in the vessel material, which then reduce its ability to withstand pressure. There is also a danger of refrigerant decomposition due to localized overheating.