I can share our experience with owning a 2008 40 PDQ for 7 years and have driven it approximately 35K miles. It has the 400 ISL Cummins engine and not having to deal with DEF fluid is a plus. Previous owner drove it for 80K miles and had the turbo and radiator replaced. Since we have owned it we installed the Watts Links which helps significantly with the wandering these coaches are known for. The RR8 box chassis flexes and the Watts link firms the chassis to axle connections curing the wandering problem. You can install the Watts Link kits yourself. Have not had to change out the steering box with the Watts Link. We have replaced the front Dometic penguin 2 A/C unit with a new Penguin 2 with mods to use the existing 5 button control box. New tires and batteries have been installed. The Dometic refrigerator runs off of electricity or propane which we like for long trips. We have added small fans inside the frig to improve the marginal performance. The king size bed is real nice for us and our dog. Two bathroom sinks do come in handy often. I do agree what many say about the quality is in the early Monaco coaches and would not hesitate to buy another early Monaco. We tow a Ford F150 extended cab loaded with a 1200 lb motorcycle trike and Kayaks on roof racks and hardly know it is there when cruising down the road. If your inspections go well and you like the condition and floor plan make the purchase.
One day at a time...
08 Monaco Diplomat 40PDQ