Finally, was able to lift up my Volvo P1800 and inspect the underneath condition. Main purpose is to check the oil leakage and suspension system.
There are oil leakage at a few places. Main one is at the fuel pump connection to the main engine block. Can see fresh engine oil leaks out from the edges. The mechanic said need to clean up and seal up that area first, then only can inspect others (on the engine part).
Overdrive seems to be leaking as well. I remembered my garage has two oil stains on the floor. One from the engine, and the other one should be from the overdrive unit. This will need to be repaired as well.
Exhaust pipes seem to be good. Some parts are rusty but should be OK.