Hi Isaia
Steve is correct in what he say, Trinidad isn´t a tourist destination and will most likely never become one. Crime is high there, and even if 99% of it is related to gang-war, drugs and other "criminal business", one can not go around by car or take a walk in the same way you can in Tobago.
Visitors aren´t targeted, but it´s easy to be on wrong place in wrong time for a visitor which haven´t been there before. It do happen that visitors been robbed, but not daily or even per week.
I remember 2-3 years two persons did ger robbed outside their hotel, on the street. But they had gold chains, camera, modern cell phones with them. A car stopped and they got robbed. Sad thing, but they didn´t use common sense.
It also happend that a group travelling to the Pitch Lake did get robbed as soon they arrived. The gang was waiting for them!
So, spend a safe, nice vacation in Tobago and everything will be just fine.
However, if you want to make a trip across, than I would suggest this place as you don´t want big hotels. Laguna Mar Beach and Nature Lodge, situated on the northen part of Trinidad, in Blanchisseuse. It´s really country side, no Malls for shopping, the road end some 3-400m further on.
Laguna Mar is own by Fred & Barbara Zollna, I know them since 1989. Fred is born i Germany, Barbara is a Trini. Have a look at their website
http://www.lagunamar.com/ and you will find information, pictures and contact information.
They can arrange a pick-up at Piarco Airport, so there´s no need to hire a car. Fred & Barbara can also give you local info about whatever, arrange tours with local drivers they know very well.
If you choose to go across for some days, I suggest that the car take the road outside Port of Spain, crossing over the mountains via Maralval, via Maracas Beach and Los Huevas Beach, you will have a small tour on the way to Laguna Mar. Back to the airport over the mountains via Arima and you have seen the central range of northen Trinidad.
Good Luck
Ronald