Vehicle involves a loan which runs over a year (8)
I believe the answer is:
calendar
'year' is the definition.
(calendar year is a kind of year)
'vehicle involves a loan' is the wordplay.
'vehicle' becomes 'car' (car is a kind of vehicle).
'involves' indicates putting letters inside.
'loan' becomes 'lend' (synonyms).
'a'+'lend'='alend'
'car' enclosing 'alend' is 'CALENDAR'.
'which runs over a' is the link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for calendar that I've seen before include "Almanac" , "List of days etc" , "list of appointments" , "Chart of times" , "that's stuffed with dates" .)