I need help i have engine odor inside interior,also strange smell in trunk,I just had a new temp sensor installed also had coolant flushed dealer recomended changing all belts, but i am still getting odors inside. The vehicle is always clean showroom condition.

Change the cabin filter. It's under the hood, way in the back. About $35. Simple DIY and a lot easier than the E36. Your mechanic probably stunk up your car...get an air freshener too.

Trunk smell? Is there water in it? Is the battery leaking? Did your mechanic put something in there temporarily?