I've had them in European cars with dainty little engines and had no problem with them but maybe the OEM supplied stuff is better quality,or the dainty little engines aren't very demanding of them.I've never seen Bosch Platinum plugs work and hold up in any thing automotive.They're worse than Champion plugs and that's saying something.
3 of The stock OEM plugs in our 8.2 GMC did that in about 4,000 miles, can’t remember the brand.The factory Bosch plugs that were used in most of the German cars were not Platinum and worked well for their intended application.The Platinum's were intended for aftermarket use and were absolute JUNK. I had a customer who had a set in a little Mazda 4 cylinder complaining about lack of power.Removing the plugs showed the center electrode burned down to the insulator.The plugs had 6,000 miles on them.That's just one of many horror stories that I personally saw.