..and DANGER WILL ROBINSON, do not lock the keys in the trunk of a Mustang convertible because in the latest version they omitted the trunk release button from the glove compartment and Thrifty don't keep spares meaning this happens:
Yes the person responsible felt suitably silly too! We also had a 300C and that had loads of space, the two cars were cheaper than an SUV or minivan for the same period.
(footnote: I looked up later on the internets and found if I had a piece of wire and a knife I could probably have popped the trunk via. the wiring loom, but obviously I didn't have the knowledge at the time and expected Thrifty to send a locksmith, not tow it from Gilroy to SFO.)