I've just bought some TPI bolts as I know they've lasted well for some people. Set of 20 including 4 eco locks came to £43.95 inc. postage. I know it's a bit more, but I also have the plastic covers on at the moment and have just taken them off as they're a right PITA!
A couple of weeks ago I saw some guy parked outside my driveway and load a trolley jack into his boot, so not sure if he was trying to take my wheels off! Reported it to the police and bought a little wifi camera to put in the lounge window just in case. Would ALWAYS have a locking wheel bolt on each corner IMO.