Do I need special wipers for my 1990 300SE? I replaced the Bosch blades (I bought the car used so this is my first replacement) with RainX Weatherbeaters 21, just as listed, but the darn things slip off after about 20 cycles.

There is an accessory attachment but the instructions say the standard J-hook fits 98% of all cars.

There is no 'click' sound when I attach the new blades but I slide them on tight. Can't see what else I need to do.

Any suggestions?