Hi Brad - I wouldn't try either company because what they do is expressly against Google Places guidelines. I can't find a link to the discussion that happened on the Google Places forum, but a Googler did declare that their practice of converting user reviews and posting it under their own profiles are against the guidelines. If I were you I would do the following:
a) Use the new respond to reviews feature to positively respond to any negative reviews.
b) Do the same for any reviews that are pulled in from DealerRater.com, Edmunds, or Insider Pages etc.
c) If you are extremely sure that the reviews are spammy or are considered slander, then you can report it and request it to be removed (there are no guarantees that Google will do this.