I just dealt with this problem last week with a new 2001 V70 XC I bought. I put my battery in that was next to new in it and "service electrical system" light came on. I had to swap out alternators. Use a multimeter and check the alternator while the car is running. If the alternator is le...

If it went out after the extra chemicals you put in id do a complete drain and fill. Then another and maybe another. Not all additives are good for our cars. Change filter of course. Does it feel like its going into gear but still does nothing?

I always drive 01 or 02 XC70 wagons. I've had problems with different tires wear patterns in pinches. The vibration is most certainly your tires. Especially if you've been messing with the suspension travel. If it got worse when you switched those tires then it's obviously your tires. CV joints usua...