I just rolled 60,000 miles today on my '05 GXP and took the car in for service. Low and behold I have a broken motor mount near the exhaust manifold. The mechanic told me he is seeing a lot of this on the V8 Bonneville'* as the miles start to get in my mileage range. The estimate to repair it is $620.00.

Thats insane, do you have a set of jack stands, a jack and basic metric hand tools? If you can find the mount some where I am sure you can change it yourself in an afternoon.

The part will cost you about 75 bucks from gm dealer at cost, takes about two hours to do, been there done that, 40,000 miles, wasn't fully broken but it was rocking around quite a bit, replaced the mount and now it feels like a new car again, the Caddy guys are having the same problems. Save yourself some serious cash and do it your self.

I have owned my GXP for 11 months. I have had two replaced under the dealer warranty. I am now hearing the tell-tale clunk from reverse to drive of my third motor mount. I am NOT running this car hard at all. I ran a 92 Firebird ten times as hard and never had a problem. Some may laugh, but I will find a way to chain that engine down when the repair is my nickel and sweat!

GM part number is 25713699 on my 2004 4.6L N*.

We have seen this here and there since the LD8 went into the Bonne. I wonder if its a hit and miss flaw in manufacturing. Some of us have really put the torque to them and never had a problem. I have always expected mine to fail, but hasn't. 48k pretty hard miles.

I would assume they are the same, but can anyone confirm the that '04 and '05 have the same part number?

Yes. the only difference is on the Title. LOL.

Has anyone come across something other than stock? Something a little more robust?

Not likely given the low number of production. I doubt it. Rockauto doesn't show one.