hoss welcome to trinidad you will find this plenty , plenty info but most useless and not dealing with the questions asked
here is some more that might be useless but it might also help
MOTOR VEHICLES
(A) Requirements
In order to qualify for any relief of taxes, the person must satisfy all the following conditions:
The person must be eighteen years old and over, and
is a citizen of Trinidad and Tobago, or
was formerly a citizen of Trinidad and Tobago, or
has citizenship of two (2) countries, one of which is Trinidad and Tobago, or
is the spouse of a person referred to in sub-paragraphs (a), (b) or (c) above;
The person is the registered owner of the vehicle for at least six (6) months prior to his return to Trinidad and Tobago;
Must have resided abroad for a continuous period of at least five (5) years immediately prior to his return to Trinidad and Tobago;
intends to reside in Trinidad and Tobago permanently;
require the vehicle for his personal use;
must import the vehicle within six (6) months prior to or after his return;
must not sell or transfer the vehicle within two (2) years of its importation.
Once all the above conditions have been satisfied then in the case of a left hand drive vehicle, the importer is not required to obtain an Import Licence.
(B) Relief from Customs Duty
Customs duty is normally payable at the following rates:
Vehicles with an engine size not exceeding 1599 cubic capacity (cc)- 20%
Vehicles with an engine size exceeding 1599 cc but not exceeding 2000 cc - 25%
Vehicles with an engine size exceeding 2000 cc - 30%
Customs duty is based on the Cost, Insurance and Freight (C.I.F.) Value of the Vehicle.
A returning national can benefit from the relief of Customs duty at the following rates:-
where s/he is the registered owner of the vehicle for more than six months but not more than one (1) year, 25% of the duty payable. In other words the importer pays 75% of the duty payable.
where s/he is the registered owner of the vehicle for more than one (1) year but not more than two (2) years, 50% relief of the duty payable
where s/he is the registered owner of the vehicle for more than two (2) years, 90% relief of the duty payable. In other words, the importer pays 10% of the duty payable.
(C) Relief from Value Added Tax (VAT)
Value Added Tax is payable at a rate of 15%. It is calculated in the following manner:
15% of the C.I.F. Value + Customs Duty = VAT Payable
There is no relief from the payment of VAT in respect of a motor vehicle imported by a returning national.
(D) Relief from Motor Vehicle Tax
Motor Vehicle Tax is normally payable at the following rates:
engine size not exceeding 1599 cc Free
engine size exceeding 1599 cc but not exceeding 1799 cc – $ 4.00 per cc
engine size exceeding 1799 cc but not exceeding 1999 cc – $ 8.00 per cc
engine size exceeding 1999 cc but not exceeding 2499 cc – $21.00 per cc
engine size exceeding 2499 cc but not exceeding 2999 cc – $25.00 per cc
engine size exceeding 2999 cc but not exceeding 3499 cc – $30.00 per cc
engine size exceeding 3499 cc – $45.00 per cc
However, a returning national may be granted relief from the payment of Motor Vehicle Tax at identical rates in the case of Customs duty as specified in (b), (aa), (bb) and (cc) above.
this web site where info was taken might be able to help you as you said you are returning from canada
http://www.ttmissions.com/faq.html
hope this helps