Get used to it. Happens to me all the time, nomather where I park either my or the wife's bimmer. It also seems to always be Ford F150 or F250's. Somehow BMW's and Corvettes act as a magnet for those. I'm not kidding. My wife tells me to always park in between two cars that are there already. At least then you know what's there and with a tad of luck they will still be there when you return. If you park way in the outfield, INVARIABLy, a Ford F150 (almost always a rustbucket to boot) will park inches next to you. Sometimes it might be something smaller like an Explorer. I've even had it where they back-parked it in instead of wedging themselves in straight.