In the comments there was this post by Daniel, it may help you:
yogi b - Its because you either need to get the Furrano or do this:
Open the _main_Furrano.cfg
Find this line: //water object
body 0.000 0.000 0.000 0.000 0.000 0.000 0.001 cars\racers\Furrano_Data\meshes_phys_chassis_water.scx ; viztest
Change Furrano_Data to Countach_Data
Save
Then you should be done ^^
But to buy it full from catalog you will be needing the Lama Performance V12 engine. I think its in the Download section, fixed by diegorborges!
Hope i helped you and anyone else that wonders