The short story "The Red Convertible" by Louise Erdrich tells of two Chippewa Native American brothers named Lyman and Henry Junior. On a trip up to Winnipeg together they spot a red Oldsmobile convertible and buy it. They then make a glorious trip across the country all the way to Alaska. It is a liberating burst of freedom, their last journey together before Henry is sent off to fight in Vietnam. When he returns, he is a changed man. He suffers from Posttraumatic Stress Disorder (PTSD) because of his experiences in the war. Lyman damages the convertible on purpose so that the work Henry has to do to repair it will snap him out of his depression. The tactic seems to succeed, and they go on one last trip together. However, Henry drowns in a river swollen with spring snowmelt, and Lyman sends the convertible into the river too.
In this story, the convertible is a symbol of the unity between Henry and Lyman. It represents the serenity that they feel in their brotherhood. In the paragraph where the brothers find the red convertible in the parking lot, Erdrich acknowledges this feeling. Discovering the car is almost like a spiritual revelation. That's why Lyman emphasizes that the car seems not just to be parked there but rather in repose.
In the Merriam-Webster Dictionary, the word "repose," when used as a verb as in this story, means "to lie at rest." When Lyman says that the car is reposing in the lot and not just parked, he is suggesting that when he and his brother find the car, it brings them a feeling of peace, tranquility, and calm. This is of great value to them, considering the circumstances around them. They are Native Americans and are frequently subjected to racism and ridicule. The country is at war, and Henry will soon be caught up in it. The red convertible represents a better life, an idealized life, a life in which they can relax, enjoy themselves, and not worry about the tumultuous world around them. That's why the word "repose" is used in this context.