The purpose of this paper was to study whether the formal vehicle specification and method of its maintenance differentiate the assessment of importance of qualitative attributes of spare parts for passenger cars. The data collection method used was a survey conducted on 498 clients of car technical service centres. The identification of the differentiating attributes was performed by applying the Kruskal-Wallis and Mann-Whitney statistical tests. The theoretic implication is the detection of qualitative attributes of spare parts, the weights of which are differentiated by vehicle specification and method of its maintenance. The practical implication is the provision of essential recommendations for the designing and manufacturing of spare parts and communication to the clients of the utility provided by the parts. As a result of the conducted study, it turned out that the vehicle brand differentiates all 21 studied attributes, vehicle servicing location – 18 attributes, origin of the vehicle – 13 attributes, vehicle age – 7 attributes, average annual number of technical service centre visits – 5 attributes, average annual mileage – 4 attributes and type of vehicle ownership – 1 attribute. A novelty element in the paper is the innovative selection of the qualitative attributes of spare parts, the use of the chosen statistical researches in the studied field and detection of the differentiation of importance of these attributes.