Rattle After New Rear Shocks

[Tropheus]

I have a 2013 2.0 TDI 140 BHP CC with 123k miles.

I had a local mechanic do the rear lower wishbones and he advised to do the springs when in there as they were original.  He noticed that one of the rear shocks was leaking and told me to make an appointment to it done.

To make a long story short, he was off sick and I decided to do the job myself.  I bought two Monroe shocks and changed them over Christmas.  I'm no stranger to a spanner and did a similar job on my wife's Superb a couple of years ago with no issues.

Job went fine and is pretty straight forward and the exact same as the Superb.  However, I now notice that I have a rattle from the rear over rough road.  I can't quite locate it - it's just vaguely in the rear.  There's no clunk over kerbs or bumps, just a rattle on rough road. I went to the trouble of taking out one of the shocks and double checking, but all was fine.

I have new rear drop links and will do them at the weekend, but I'm not convinced that's the issue.  It's very coincidental that this started after I did the shocks.  I mentioned it to my mechanic and he says that it could be just that the new shocks are stiffer and are now bringing out vibrations.  I think it's too coincidental.

Maybe the Monroes don't suit the car?  I have them on the front with no issues.