Engine mounts, noise and vibration

[DW42]

Over the past year or so my 1992 240 became increasingly noisy, accompanied by vibration. Underneath I saw an obvious problem -- welds on the exhaust back box had broken and the back box was unpeeling, making contact with the underside of the car. I replaced the exhaust from the cat back, looking forward to peace and quiet. I started it up, and it was even noisier. I checked and re-checked the joins on the new exhaust and everything was tight. I thought I might have bought a crap exhaust. With some further peering at the engine I noticed that one of the not very old engine mounts had a strange gap in it. It turns out that the noise and vibration was caused by 5 year-old mounts collapsing. When replacing the exhaust, I whacked the front box backwards with a rubber mallet to remove it. In doing so the mounts collapsed even further, resulting in even more noise and vibration. With new blue box Volvo mounts it feels like I'm driving a new car. The failed mounts were urethane, which I expected to last longer than rubber. They lasted about 25000km. Are blue box mounts still the way to go? I don't like replacing engine mounts!