This thesis' work has been conducted at and made possible by Autoliv Sverige AB in Vårgårda. The aim of this thesis is to study how the occupant experience of the belt changes when it is moved from a traditional installation point in the car's B-pillar, to the seat. This shall be studied in terms of how the perceived comfort is influenced by a belt in seat in an upright and a reclined seat back position of 20 and 45 degrees, for different sizes of occupants. Also how the ability to reach a belt in seat is affected by the size and mobility of the occupant. Based on this new knowledge, an optimal outlet position for a belt in seat shall be proposed, from a comfort perspective. The work has used a cross-sectional research approach to achieve its purpose. Through the cross-sectional approach, several different qualitative and quantitative methods have been used. Initially, a literature study where subjects relevant to the forthcoming study was studied. Meanwhile, a competitive analysis of existing belt in seat installations in new cars available on the market was planned and carried out. In the main element of this work, a two-part comfort and mobility study with a belt in seat was performed. The study combined the methods interview, survey and observation. Through the interview, qualitative questions were asked as a complement to the quantitative responses given by the test subjects on scales in the survey. Observations were used to observe the subjects' behavior and difficulties regarding the belt in seat. A major limitation of the results of the study is the deficient distribution of sitting heights and genders in the group of test subjects, which founded a certain bias in the results. This has been the reason why it has not been possible to draw any certain conclusions from the results, however, some trends have been seen. The comfort study revealed several different assessments of the belt that contributed to discomfort, including the perception of the belt being too close to the neck or too far out on the shoulder. Additionally, the discomfort significantly impaired when the seat was reclined to the relaxed state. The mobility study showed that more subjects felt limited by their own bodies in the movement than by the belt. In addition did the reversed belt geometry create large discomfort issues at the neck. An important conclusion of this thesis is that the seat's design is as important to the customer experience of discomfort of the belt as the positioning of the outlet. It has also become clear that the accessibility of a belt in seat is strongly limited, as it was tested in this study.