I've stripped down (to varying degrees) a couple of estima, both diesel, so I know a bit about their construction. I'm not sure what you mean though. In diesels, the engine oil is located under the bonnet. It is fastened with two small (size 12 head)bolts, one of them is attached to the air intake, the other the front of the car body, and it sits above to the left front corner of the battery. The oil container is clear allowing the visibility of the oil level. I was wondering, do you have a diesel? cause it soundz like you do. The oil runs through the alternator, but I'm not exactly sure how the engine oil level is maintained, and how the pressure system would stop the oil from rising above the oil rings on the pistons while keeping the oil level at its optimum level. But the alternator is definitely a major part of that solution... its an interesting set up. I'm also surprised, cause the set up obviously allows the oil to remain clean, unless it doesn't circulate as I imagine it would? I'm not sure what button on the dash you're talking about. hi yes it is a diesel and i have since found out the bottle i was talking about is for the engine oil it has a valve when the engine level drops it adds some thanks john