We kept Rotella in the trunk of the 240D through two AZ summers without issue a couple of years ago. Must be some new packaging thing.
We did however keep it inside a rubbermaid tote with other essential stuff. Personally I wouldn't put any container of any automotive fluid on bare carpet in a trunk.

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You're a daisy if you do.
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84 Euro 240D 4spd. 220.5k sold
04 Honda Element AWD
1985 F150 XLT 4x4, 351W with 270k miles, hay hauler
1997 Suzuki Sidekick 4x4
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