Compensation Events are assessed as the effect on Defined Cost(CL63.1). Therefore the vehicles can be included in a compensation event quotation if they are Defined Cost, i.e. they satisfy the requirements of the Shorter Schedule of Cost Components.
The main requirements are:
Cost is incurred to Provide the Works
The Equipment is used within the Working Areas.
The relevant clauses to look at are:
Core Clause 11.2(13)-Definition of To Provide the Works
Option A Clause 11.2(20)-Definition of Defined Cost
Shorter Schedule of Cost Components: Main Introduction and Section 2(Equipment) Introduction.
Contract Data Part 2 will describe the Working Areas.
I hope this answers your question, but if not, please let me know and reply further.