Let me get this straight.
PM is working in Okatie and using the old farm truck rather than his F150 Platinum that is exactly like JMM's. This is because PM's F150 is in the shop.
JMM gets a call from RM4 asking him if he can take RM3 to his doctor's appointment (in Savannah, I believe) as RM3 is having trouble breathing, but RM4 cannot make the entire trip himself as he has time sensitive appointments later in the day.
JMM agrees and they decide to meet halfway, in Ridgeland. RM4 drives RM3 to Ridgeland in RM3's car. JMM chooses to drive to Ridgeland in PM's old farm truck rather than his own pickup (which he leaves in Okatie for PM).
Why would JMM choose to take the old farm truck for this important trip where a breakdown would be a major inconvenience (since a breakdown could delay JMM meeting to pickup RM3 or, if the breakdown occurs after JMM and RM3 continue on in RM3's vehicle could delay RM4 from getting to his time sensitive meetings)?
Why wouldn't JMM take his own F150 and let PM take the farm truck?