Ex-USF1 nee Ex-Brawn trailers on ebay
USF1's 2 race transport trailers were seized by English court order and are being auctioned by the Sheriff on eBay to pay off a creditor(s?) of USF1. Not exactly Grassroots but you would arrive in style! My favorite part of the listing: "As stated above, the trailer was previously owned by Brawn GP and this trailer is currently sign written with their logo and the name Jenson Button 22 on the side. This may infringe on copyright and/or trademark law and it is recommended the purchaser removes this livery upon collection."
hotlinked for your pleasure
edit - doh! hotlink blocked!
