Custom Plugin Request

i want to ask if is possible to enfold team to make personal custom plugin for enfold theme website?

i want to make custom plugin for my admin to enter specific database for member, member can only be created by the admin , password and username will be sent by email, member can only view this database.

this is the actual story if to be clear of my request :
this is a garage website where member can use their car service history in the garage by login to their account, account will be created based on car number, so 1 email can be used for many account assuming 1 person might have more than 1 car .. the membership on this website created when they visit the garage and do some car service, changing tire, oil replacement, etc. the admin will create the account for the member, each account consist of basic car and car owner information such as : car brand, model, year of production, color, owner name, first time service date; and also their service history: Type of Services, Mileage, Date, Description, and quantity

is it possible? how much the cost? what should i do when enfold/wordpress have an update?

thanks before..

Regards,
R. Jonathan M.