The subject is missing from this sentence: "Drives in the city during the evening rush hour." It has an active verb (drives), but does not tell you who drives. Who is driving can be a person's literal name, or it can be a pronoun, such as he or she (is/was) drives in the city during the evening rush hour.
"In the hiding place that Carl had been using for years." This is an incomplete sentence because it tells us where, who, and how long, but doesn't tell us what about it. What is happening in the hiding place? Who is it happening to? Why are we discussing it? What about it?
"When we finally heard that she had made the dress herself." This is a sentence fragment because it begins with a time period. However, it has a subject ("we") and a passive verb ("heard"), but doesn't tell us what happened when "we" heard that she had made the dress herself. Did "we" applaud or congratulate her? Why did we "finally" hear she made the dress herself? The word "finally" indicates that there may have been a reason the information was not given or heard immediately.
"When I got home. I made myself a Pepsi float." This sentence fragment is easily corrected by using a comma instead of a period, or by switching the two partial sentences around with no punctuation at all. "I made myself a Pepsi float when I got home." or "When I got home, I made myself a Pepsi float." The sentence fragment can also be remedied by dropping the first fragment all together: "I made myself a Pepsi float."