If you mean excessive vibration from engine usually there are three possible causes, can come from engine mountings as you suggested, dual mass flywheel or crankshaft belt pulley, all these items are anti vibration damped within their assemblies.
If crank pulley was delaminating then you would possibly see runout of drivebelt, dual mass flywheel most likely would be felt during clutch pedal operation, engine mounts mainly when selecting reverse then forward gears.
If high mileage then all three could be suspect assuming exhaust assembly is secure on its hangars and heatshield
isnt hanging loose etc.
Hope this useful for you 

Koni fsds on rear makes biggest difference to mine along with Fiat coupe/ Alfa Gtv rear bump stops, Febi part number 36979, only thing I havent tried is 16" wheels and tyres, 40 profile 17's on mine and I find myself clenching my teeth often on approach to rough surfaces..But its been utterly reliable and wouldnt change it for anything else even after near 11yrs  of ownership.