I will have to try to use the nimrud template. There might have been some problems and there's the advantage of having a pre-existing texture, which is known to work - this makes it much more easier for me by being able to imitate key coordinates and positions of nodes and labels.

For now, here's how far I got with the old one: http://ompldr.org/vZXNjcw

previews:

http://i.imgur.com/ORBRJ.jpg | http://i.imgur.com/uP8Xy.jpg | http://i.imgur.com/Z6XfV.jpg

Some inspiration images: http://i.imgur.com/MBM7V.jpg

Thanks, farrer! I recommend using pixel measurements in Inkscape.

Some info about the textures/cars: I invented brands and car model names to replace the real ones:

"Evaluate Pi" by "Tex Technologies"/"Tex Technologies Sports"

"Cordon" by "Rotor Automobiles"/"Rotor"

"Fox Mark II" by "Iron Precisions"

The whole context of the game is an event called "TRI" or "Trigger Championship". (Maybe "TRC"/"Trigger Rally Championship" would be better).

Ads are open source program or library names. Real logos are being avoided. There's a freesound ad on the Cordon and there will be an opengameart ad on the Fox.

Here's my Fox WIP: http://ompldr.org/vZXJraQ I'm actually so proud of the tire that I put it on OCAL http://openclipart.org/detail/171197 :)

Can attribution be used to change the license?

No, the summary text is not specific enough for the license to be interpreted as "the author has control of any marketing of a work that contains their work". In fact there is no "author can chose attribution" statement in the legal license text, although the author can decide whether their name or nick and/or website/email is shown.

 and everywhere else where the creators/contributors are listed

this clearly means "everywhere in the game".

I assume this doesn't include a list of authors/contributors that sits on the projects wiki

What list of authors/contributors on the wiki? The wiki contributors? Or a game contributors page on the wiki? If it's the first, the two are unrelated. If it's the second, then I guess all the credits in-game, on-website and in-filesystem should be pretty much be the same (I can only recommend linking to the in-filesystem credits page from the website, see http://trigger-rally.sourceforge.net/ for a simple solution).

As for "connection with", "sponsorship" and "endorsment": as long as you don't claim that the author made their work for your project, you're not doing any of these things.

Example: "Made by X" vs. "Made by X for OURPROJECT"

You need to read all of 4. b.:

If You Distribute, or Publicly Perform the Work or any Adaptations or Collections, You must, unless a request has been made pursuant to Section 4(a), keep intact all copyright notices for the Work and provide, reasonable to the medium or means You are utilizing: (i) the name of the Original Author (or pseudonym, if applicable) if supplied, and/or if the Original Author and/or Licensor designate another party or parties (e.g., a sponsor institute, publishing entity, journal) for attribution ("Attribution Parties") in Licensor's copyright notice, terms of service or by other reasonable means, the name of such party or parties; (ii) the title of the Work if supplied; (iii) to the extent reasonably practicable, the URI, if any, that Licensor specifies to be associated with the Work, unless such URI does not refer to the copyright notice or licensing information for the Work; and (iv) , consistent with Section 3(b), in the case of an Adaptation, a credit identifying the use of the Work in the Adaptation (e.g., "French translation of the Work by Original Author," or "Screenplay based on original Work by Original Author"). The credit required by this Section 4 (b) may be implemented in any reasonable manner; provided, however, that in the case of a Adaptation or Collection, at a minimum such credit will appear, if a credit for all contributing authors of the Adaptation or Collection appears, then as part of these credits and in a manner at least as prominent as the credits for the other contributing authors. For the avoidance of doubt, You may only use the credit required by this Section for the purpose of attribution in the manner set out above and, by exercising Your rights under this License, You may not implicitly or explicitly assert or imply any connection with, sponsorship or endorsement by the Original Author, Licensor and/or Attribution Parties, as appropriate, of You or Your use of the Work, without the separate, express prior written permission of the Original Author, Licensor and/or Attribution Parties.