Knocking and Vibrating

My car (2000 Mitsubishi Magna Sports 3.5L dual trans) is making a knocking sound only when the engine is warmed up on the right hand side and when i get to 110Km’s the front of the car and steering wheel start vibrating and shaking heavily only when my foot is on the acclelarator. Foot off it stops, foot on over 110kms it starts. Mechanics diagnoses so far: Brisbane Mechanic -its your suspension $900, Pedders – suspension is 100% its your drive shaft and power steering rack $1500 Car Drives Brisbane to Melbourne. Ultra Tune -your drive shaft and rack are fine its your engine mount -$200- 2 hours later -your engine mount is fine its your transmission and unsafe to drive-$2800. Transmission place- transmission is 100% nothing wrong with it. Drove the car to Adelaide and car is still running but still knocking and vibrating.