when the top mount went on my megane, it was only noticeable when under load, IE corning hard, and it was more of knocking feeling, as said above you could try jacking the car up and give the wheel a good wobble and see if there is any play in the wheel, could be a drive shaft on the way out
My money would be on CV joint, have a look at them and see if any have had the clips replaced with jubilee clips / universal CV boot clips, if they've failed and been left for a while before someones noticed or they've not put enough grease in when repairing then there's a high chance of increased wear, might be the CV joint on its way to wearing out!