Hi Sarah,
At that time the Volvo UK Touring Car Racing Team was operated by TWR (Tom Walkinshaw Racing). The company did used to retain and keep a collection of most of the vehicles that they competed with, but sadly following a failed attempt to conquer F1 in the late 1990's, the company went bankrupt in 2002 and all of it's assets were auctioned off including most of the car collection.
https://en.wikipedia.org/wiki/Tom_Walkinshaw_Racing
However there is a Swedish chap who has been buying some of them back, you might be able to track him down. I don't know him personally, I came to know about him when I was Googling myself a few years ago.
https://www.youtube.com/watch?v=kkvIQuNGs6k
You might also get a few more hits of you post in the "Volvo and General Motoring" thread in the generic pages of this forum.