Electrical suppressors are fitted to the item that's creating the interference, not the radio.
MW interference can be a pig to get rid of; it could be any number of things, but seeing as it's only present while accelerating I would say that it's engine/charging related.
If the noise is a sort of scream sound then it would point to the alternator.
If it's a kind of buzzing (and you have a petrol engine) then iot would point towards the ignition system.
Anything beyond that is going to take some intense looking at.