Resistance spot welding (RSW) emerged in the 1950s, and is now the predominant assembly technique in the automotive industry. A spot weld consists of three regions, which have different material properties - a weld nugget with a cylindrical shape, a heat-affected zone (HAZ) and the base material sheets. For instance, the yield stress in the nugget is up to three times higher than in the base material, and the plastic properties of the HAZ are non-homogeneous. Due to the applied pressure by the electrodes during the welding, the thickness of the nugget is often less than the thickness of the two metal sheets. This so-called nugget indentation is typically not significant for plates up to 1 mm, but is more pronounced when thick plates are assembled. Stress concentration may occur at the edges where a change of thickness takes place, which may result in crack initiation. The transient heating and cooling results in hardening of the material, and a pre-stress may remain after cooling. A typical vehicle body-in-white is made of steel sheets and contains about 4000 spot welds. The optimal diameter and distance between two successive spot welds are determined by the sheet thickness. The diameters range from 3 to 7 mm, with a mean of 6 mm. The manufacturing practice of spot welds in the vehicle assembly process poses constraints on the spot weld layout design, as not all positions can (effectively) be reached. Also the assembly process is not perfect - sometimes a few spot welds are even missing or broken right from the beginning of the vehicle life. Furthermore, spot welds are highly susceptible to fatigue, so that a substantial number may fail during the vehicle lifetime. The scope of this article is two-fold. First, the impact of spot weld quality and design on a vehicle's functional performance is reviewed, addressing strength and stiffness, NVH and durability. The overview briefly covers both experimental tests and predictive finite element (FE) modelling approaches, explains the complexity of a spot weld design problem and discusses optimisation strategies. Second, an industrial robustness study is presented, that assesses the effect of spot weld failure on dynamic vehicle characteristics. Damaged models are generated automatically, by breaking a subset of the vehicle's spot welds, using a weighted uniform selection probability. Monte Carlo simulations are then used to assess the scatter on dynamic vehicle characteristics.