Need to know your DB name to suggest appropriate answer. It's not pivot rather string aggregation. I will try to cover major RDBMs.

If you are using sql server or postgres you can use string_agg()

Query:

select Car_ID,Car_Name,string_agg(Owner,',') as Owners from Cars
group by Car_ID,Car_Name

Output:

fiddle

If you are using MySql then you can use group_concat() :

Query:

select Car_ID,Car_Name,group_concat(Owner) as Owners from Cars
group by Car_ID,Car_Name

Output:

fiddle

If you are using Oracle then you can use listagg() for this purpose:

Query:

select Car_ID,Car_Name,listagg(Owner,',') as Owners from Cars
group by Car_ID,Car_Name

Output:

fiddle