As you probably know, the 300C was on Car&Driver's 10-best list when it came out, so it's a great car to start with. My mom has a '97 Chyrsler T&C, and it has been excellent! She just had to replace a vacuum pressure transducer on it, but for having 170k miles, it's been excellent, so I would expect the 300C will easily last over 150k without any major problems, but there's no guarantee on anything: it depends on so many factors, primarily on how well it was cared for.