I have a couple of questions. The first one is that my 2006 BMW z4 with an automatic and also has the sport button. I recently noticed that when I accelerate going up hill, I can feel a slight vibration and from watching your Youtube show, it could be the high gear in the transmission. the car has 124,000 miles and I take very good care of it. I notice that if give it more gas, the vibrations seems to go away but of course, the car is downshifting. Is this something that will cause me a lot of grief or just ignore it. The car is 15 years old and I bought it used. It had 105,000 already on it when I purchased it.  I have no idea if the fluid as ever been changed so I am afraid to start now.  The second question is in reference to my 2008 Nissan Maxima. When I start the car, I turn the switch till the motor turns over a couple of times. I let go and then start the car. I have to do that after the car sits over a few minutes. I was advised that the fuel pump could be going bad since the car has 168,000 miles. On a Nissan, I am actually driving on borrowed time. I replaced the fuel pump. Same result. I was going to buy and install new fuel injectors but you mentioned in one of your shows that they need to be balanced. This is the show where a person replaced the engine in his hummer and also the injectors and still had a misfire on number 4 cylinder. What else could be causing this. The fuel filter is in the pump. I thought that the problem could be in a leaking injector and that is why I keep loosing pressure between the pump and the engine. Any help would be appreciated.

2006 BMW Z4 3.0i automatic

124,000 miles