1999 is the first year that the 70 series used the electronic throttle module, or ETM. Very high rate of failure , esp after 70K miles. There is a class action suit pending against Volvo because of the high rate (I have heard of something like an 85 percent failure rate). If it fails, usually without warning, you lose throttle control and end up limping along at idle speed. Better hope it doesn't happen on an interstate with a semi breathing down your neck and there's 4 lanes of traffic to get across to the shoulder. Do a google on Volvo + ETM, and or check out the xc70.com forums on this subject. If I was buying a 1999-2001 70 series I would insist on dealer replacement of the ETM as a condition of sale, and an extended warranty on it on top of that. They go for around a grand to replace. Have given Volvo's reliability reputation a big and apperenty well deserved black eye for the way they have been trying to dodge responsibility. I just dodged the ETM bullet, my recently purchased 98 V70 XC Cross Country was the last year of the series that had a nice simple cable and spring controlled throttle body. Why they went from something cheap, simple and reliable to a electrical servo motor driven throttle body that costs a grand to replace and has an abysmal failure rate is beyond me.