I make some polls on my website, like :
What do you prefer Ford Explorer or Toyota 4Runner?
Is such a poll allowed without explicit permission of Toyota and Ford?
Can I use their logos?
Can I use car photos? (when I take them from wikipedia and they are copyright free?)
Using logos of the companies is in most instances fine, and falls under the terms of fair use. The use of photos of the cars on the other hand is trickier because unless you are given permission by company, you could be infringing on copyright ownership to those images.
A better solution would be to take photos of the vehicles yourself and then post. Or use a photos of the vehicles from Flickr or Google images with a Creative Commons license that allows for that type of use. You can search images using the websites' advanced search engine. The Creative Commons website can give you tips on how to phrase attribution in the photo credit.
In the United States anyway it is perfectly fine to:
Do survey questions where you mention specific products or trade names. When using terms that are registered trademarks (like Ford and Toyota) it is a good idea to have a footnote on your page to the effect that "Various trademarks appearing on this page are the property of their respective owners."
You can use photos to which you have rights. In the case of photos explicitly placed in the public domain you have been given rights. It is still a good idea, but not required, to give credit to the person who took the photo (caption like "photo by Bill Smith, used with permission").
You can probably use the logos as part of the survey, but this could be a grey area. For this you may want to seek professional advice because if you use them improperly there could be negative consequences.