These are 2 of my fave AH fics.
Wicked Ways by noaluvjames
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=13282&warning=NC-17Summary: It's punk princess Buffy with a snarky attitude and uptight Spike, a wall street broker who used to be a rebel (also answer the name of William). Buffy's stepbrother, Xander a pub owner is too lazy to drive her to college, a day's drive away. Choosing the easy way out he asked his old pal Spike for a favor...only things are not as easy as they seem. Will snappy Buffy drive reformed Spike completely insane or bring out the best in him? ... A Spuffy road trip with a twist. Complete
Driving to Distraction by BittenAndStaked
http://web.archive.org/web/20080619133230/http://www.talesoftheslayer.com/drivingtodi straction/drivingtodistraction01.phpBuffy decided to stake her independence by making her own way across the country to her college, but didn't bank on not having the money to get her and her things flown to Sunnydale. Enter William, the car share who seems more like a nightmare. Complete
Links to lots more in general.
https://www.spikeluver.com/Forum/index.php?action=vthread&forum=5&topic=1645