QUOTE
Due of high density
of words related to cars, Google will consider the reciprocal as comming
from a site with a same theme ? Take into consideration that in title tag
of page containing the car gategory is written something related to newsletters.
The PAGE has information about cars. So, they are related on the page level. Now, does your site about cars offer a newsletter? If so, then you'll get a little bonus punch for your buck. See, on that site, it's likely to be structured in a way that every page on the site deals with the primary concept of "newsletters" (in the same way that every page on High Rankings deals with the primary concept of "Search Engine Optimization"). The page that links to you is about "Newsletters with a focus on Cars" (in the same way that this thread is about "Search Engine Optimization with a focus on Reciprocal Linking").
Ideally, you wouldn't have that site link to your homepage, but rather, you'd have it link to your newsletter subscription/information page. And, your outbound link would point to the most relevant page on that site - most probably the cars category that contains your link.
See, this is another problem with the way that people do reciprocal linking - something that leads to the perpetuation of the Recips Are Dead Theory. Let's use your example here, for a moment.
You have an inbound link going to a "cars" page (and since it's your top page, there probably isn't a clear focus subset). It is coming in from a "Newsletters -> Cars" page, so it's obvious that that page is related to yours in some way.
Now, you have a link back out from, I presume, a links page that is "Cars -> Links" for its subject and focus. But, you're pointing out to the front page of that site so you're saying that your "Cars -> Links" page is somehow related to the "Newsletters" page. But how? There are no common copy elements on both pages as there are with the link that goes into your site. And, so, your outbound link isn't considered to be relevant. They have a page that's clearly related to yours, but you don't have a page that's clearly related to them.
So, in this case, the Newsletter Site clearly gets the biggest benefit. They are saying this page about "Newsletters -> Cars" is related to this page about "Cars". And it can be verified by checking the text on the cars page that at least things match up on the subcategory level. So, the newsletter linking page gets a little boost because it says it's about cars in some way and it links out to pages that are about cars in some way. Everything is relevant and it gets a little boost towards becoming an authority site.
In your case, you're saying that your links page is about cars with no other subcategory other than "links" which is very broad. You link to a page about newsletters and thus, you are saying that your page somehow relates to newsletters, but there is no corresponding evidence on your page, other than the link, to corroborate with this.
You'll get a little bit of PR from your inbound link from them, but raw PR really doesn't have the power it used to. Topic Sensitive PR is king.
When doing links out of your site, you rather need to think of it in the same way that you think when you submit to a directory like the DMOZ. When you submit there, you are expected to find the most relevant and specific available category (or page) to submit it to. When linking out, you should also link from your specific most relevant page to the specific page you're linking to. If you don't have a page that's relevant to the page you're linking to on the other site, then you shouldn't be exchanging links in the first place.
Reciprocal links work just fine if they go "from specific to most related specific" and "to specific from most related specific". Linking from a general links page to the front page of another site is, in fact, dead.
G.