Well that's a shame that you ran into those many problems with your LS400... Parts do wear out over time on these cars with 130,000 miles, like LCA bushings, LCD lighting, maybe water pump, timing belts and few other trivial stuff... When neglected they could lead to more serious issues.. Still the car should not have had those problems....Driveshaft, etc... Never heard of that in all my years of dealing with these cars..... So sorry.....
Also the SS Chevy Nova muscle car and 74 model Chevy Nova with the bullet proof inline six motor is actually one of the better American made cars made for it's time.... I had owned a 74 and had very little problems with it up until 200,000 miles... A very solid older car.....