This was the Sport Relief Top Gear special called Top Ground Gear Force. it was shown between Series 10 & 11.
There isnt a IMDb page for it (wikipedia does have one although not always reliable but its page does seem to be).
Unsure if this should be in top gear, possibly as 11.00 since it was a special. You decide.
(Creditation to dragonboy)
3 Stars - Caterpillar 301.6C

3 Stars - Caterpillar 308C CR

3 Stars - Unknown MAN

2 Stars - KATO CR-100

2 Stars - DAF LF

1 Star - SEAT Alhambra

1 Star - Unknown Scania