You can check the integrity of the two round ones shown in J3SVT's post above, (fore & aft "roll-resistors") by just leaving the car in gear/Park, opening the hood, grab one of the front tires, and rock the car back and forth. If you look at the top of your engine and see a significant amount of movement while rocking it back and forth, those two mounts are probably weak.
The Engine/Transmission mounts are located on the driver and passenger side of the engine. The passenger side one is easily visible attached to the under-side of the large Black horseshoe shaped forging attached to the front and back of the cylinder head on the serpentine belt side of the engine. You really cant tell too much by looking at the mount, other than possibly the "lug" that extends through a slot in the mount portion bolted to the fenderwell may be riding pretty low in the slot. The Drivers side "Transmission" mount is only visible by removing the airbox.
The best indication of failing Engine/Transmission mounts is the amount of gap between the underside of the Transmission and the main sub-frame member on the driver's side. If you turn the wheels all the way to the Left, then look into the wheel-well behind the front side of the left wheel, there should be 3/8ths to 1/2 inch of space between the sub-frame and the bottom of the Tranmission case. If the case is sitting on the sub-frame, the mount has sagged to the point it should be replaced.
I've seen your previous posts about annoying vibration when your car is at idle in Drive. I strongly suggest you replace your Serpentine Belt and Tensioner to try and resolve it.
PS. You'd really be helping people Help You if you'd put what Year, Make, Model, Engine, and Transmission configuration you have into a "Signature" line at the bottom of your posts.
(Like you see below)
