Firsty, Welcome to TOCAU now the oily stuff The oil leaks you are getting are related to a tiny crack in the rocker cover gasket. so these needs replacement asap, before you get a blow out! You can DIY (the 4cyl is easy, V6 is a bit more tricky) or get it done by a local grease monkey! should be about $400~ as for the clunking sound from the back, I have the same problem. it is the suspension. mine is in dire need of change as is it 184,000km old! Power steering rack, could be a worne seal somewhere. but leave that to an expert, otherwise you'll have nuffin!