The 'Monkey up a tree Jack' is a VW Beetle jack. They are quite cheap
and easy to obtain. There are several on ebay (one is item no.
2469695649 which also has a photo). For rallying you really need to
weld a plate on the base for use in the forest and improve stability.
You can also decide whether to use square tubes welded into the rally
car sill for operation or to modify as per Ford Escort Rally
Preparation (published by Ford motor Company - now available
reprinted) page134.