Final answer:
A ricer car refers to a car with excessive cosmetic modifications which do not enhance the car's performance and are often considered stylistically exaggerated or in poor taste.
Step-by-step explanation:
A "ricer" car typically refers to option b: A car with excessive cosmetic modifications that are often considered to lack performance enhancements to match their appearance. The term is sometimes used pejoratively to describe a car that has been modified in a way that is considered to be overly flashy or in poor taste, often with modifications that have no benefit to the car's performance, and sometimes may even hinder it.
Despite the increasing fuel efficiency of modern vehicles as mentioned in reference point a, and noneconomic factors such as a cold winter as cited in point b, these are not related to the definition of what constitutes a ricer car. Therefore, the most accurate choice from the options provided would be the one concerning cosmetic modifications.