Connectivity in vehicular ad hoc networks tends to be vulnerable. This is mostly because of the influence of road's traffic parameters like traffic flow and vehicle's speed. One possible way to improve the connectivity is to add some nodes with higher transmission range. These nodes also could give some commercial services to the vehicles on roads (i.e. audio/video service, traffic information, etc.). In this paper we study the connectivity in presence of these nodes which we call mobile base-stations. Our approach is based on the work of Miorandi and Altman [11] that transformed the problem of connectivity distance distribution into that of the distribution of the busy period of an equivalent infinite server queue. We study the effects of mobile base-stations on the connectivity distance and number of nodes in a spatial cluster (platoon). In our investigation we use some publicly available statistical data and realistic traffic patterns. Our model can be used to obtain optimum values for number of base-stations and their transmission range in order to achieve intended degree of connectivity.