I seem to remember reading somewhere about Rossi in Schumacher's car.
oh, here it is, from last year (excerpt):
http://sports.espn.go.com/rpm/news/story?id=1787125
Schumacher impressed
Schumacher believes Rossi has what it takes to switch from two wheels to four.
However, the six-time Formula One champion questioned whether the Italian would be able to make the grade at the very highest level.
Rossi, 25, impressed Schumacher with a secret Ferrari test at the team's Fiorano test track on Wednesday, lapping the circuit in under a minute in the German's F1 car.
"He got on pretty good. He took some time to get into it but in the end I think he handled it very impressively," Schumacher told a news conference before Sunday's San Marino Grand Prix where he seeks his fourth win in four races.
"Once you have the racing blood then you sort of know what to do.
"He has great ability, he has shown that many times on his racing bike and he has shown that to some degree in what he did yesterday," added Schumacher.
"He knows how much basic knowledge and experience you need in the lower classes to build up to this top level," the German said.
"I would probably say he would come to a certain level which would be maybe competitive but to come to the final bit is usually the difficult bit.
"But I don't think it is the point because he just wanted to enjoy himself and I'm pretty sure he did, looking at the grin he had on his face yesterday.
Briton John Surtees, still the only man to win titles on two wheels and four, has urged Rossi to quit MotoGP for Formula One.
"Valentino should move to Formula One and he should do it now. He has the right age and the right motivation, he shouldn't waste any time," the 70-year-old told the Gazzetta dello Sport before Rossi's test.
Motorcycling world champions have made the switch with varying degrees of success.
Surtees won the F1 title with Ferrari in 1964, despite scoring fewer points than compatriot Graham Hill, because only the six best results counted. He had previously won seven motorcycling world titles.
Briton Mike 'The Bike' Hailwood raced for Lotus, Surtees and McLaren from 1963 to 1974 with a second place at the 1972 Italian Grand Prix.
Most recently Venezuelan Johnny Cecotto competed in 18 Formula One grands prix for Theodore and Toleman from 1983-84.
Rossi won the first race of the MotoGP season for Yamaha last weekend after years of domination with Honda. In the process he became the first rider to win successive races with different manufacturers.