We study a sequential second-price auction for allocating wireless resources between two non-cooperative users. This mechanism requires relatively little computation and information exchange among agents, but does not always achieve an efficient allocation. This is a continuation of previous work in which the worst-case efficiency is evaluated, assuming each user has full knowledge of the other user's utility function. Here we assume that the users are randomly placed within a region, and evaluate the associated efficiency via simulation. Sequential auctions for bandwidth (with fixed power) and for power (with fixed bandwidth) are considered, where each user utility is the achievable rate, and interference is treated as background noise. Our results show that the sequential auction typically achieves the efficient (utility-maximizing) allocation. We also relate observed improvements in the worst-case efficiency to constraints on the size of the marginal utilities associated with each resource.