Jennifer Lopez was upstaged at the American Music Awards Sunday night. By a car. But this wasn’t just any car. It was a Fiat 500. The same Fiat featured in her “Papi” video. The same Fiat in the 30-second trailer promoting that video.  The same Fiat she endorses in commercials. (btw, I mention Fiat in this post about 16 times. I can use a new car).

Earlier this year Fiat enlisted the help of Lopez to promote its cars. The collaboration included a staring role for the 2012 Fiat 500 convertible in her “Papi” music video (which is riddled with product placement spots) and trailer and appearances by Lopez in the “My World” and “Elegance” commercials for the Fiat 500 Cabrio and the special-edition Fiat 500 by Gucci. And apparently, the deal also included an invite to the AMAs.

It’s not like Lopez is the first star to include product placement in her videos, license her songs for an ad or even star in a commercial. Prior to the late 90s, most artists refused to cross the line in the art vs. commerce debate, keeping their songs free from commercial use. But by 1999, a gradual shift toward a reciprocal relationship between advertising and pop music transpired in the music industry. That year, electronic artists Moby licensed his entire album Play for use in commercials, movies and television. In 2000, Nick Drake’s “Pink Moon” famously played in a Volkswagen commercial. Indie bands realized they gained exposure through television commercials and musicians jumped on the bandwagon. Then bigger artist such as U2 and Coldplay released songs for artsy iPod commercials. And pop stars have endorsed products for years. Pepsi’s latest ad recalls its celebrity promoters from Michael Jackson to Britany Spears to Kanye West.

Fans seem to have soften their views on “selling out”—whether because the trend was gradual or they knew smaller bands have a difficult time securing radio play or they are sympathetic to a struggling music industry and know musicians must make money to continue to make music.

Yet when an almost naked Lopez interrupts her gyrating dance routine to hop into a spinning car onstage—a car that bears no meaning to the song whatsoever except to make sales—she goes so far past the art vs. commerce line that it stings a little.

While music critics consistently mention the idea of authenticity, pop music usually gets a little bit of pass. But Lopez has taken it to a whole new level. In a recent article analyzing the pop music identity and Lopez, critic Ann Powers writes, “Reality got a little too heavy for Jennifer Lopez at a performance in Connecticut last week. Singing a ballad about monogamy while surrounded by a chorus line of dancers dressed to resemble the frequently married star’s famous exes, and then confronted with a gigantic projected image of herself holding her twin children in a Gucci ad, Lopez broke down in tears. ‘I’m just a girl, like everybody else, trying to find my way,’ she later told a reporter. But she also intimated that her loss of composure was, at least in part, an act.”

Although Lopez may not have been completely faking her emotions, she did put on a bit of a show with her tears. Powers says, “Artists give of themselves within their work, but pop stars are also marketing themselves — their private lives are a valuable commodity.”

In today’s music world, artists must build relationships with their fans. Lopez’s tears elicited sympathy from her fans. She knew crying and putting her feelings on display created a connection.

“I think that they felt what I felt, which is, you know, I’m just a girl, just like everybody else, trying to find my way,” she told Access Hollywood. “I felt like they got that, and they understood it, and we were all like one at that moment.”

But Lopez can kiss all that sympathy goodbye—at least until the staunch of that Fiat wears off. She’s received a lot of backlash. The Los Angeles Times wrote “the most cringe-inducing, embarrassing performance of the night.” AdNews reported “Tweets about her performance ranged from: ‘Remember that time we saw J.Lo cruising down the street in her Fiat? Me neither.’ to ‘J-Lo + Fiat 500 at the AMA’s = pathetic Is there no dignity with regards to product placement?’”

Olivier Francois, Chrysler’s CMO, said “Jennifer fits perfectly with the brand not because of who she is but because of what she is — authentic, passionate, modern and a fighter determined to stand out from the rest.”

I hope Francois and Lopez realize that the blatant display of advertising during the performance strips her of any authenticity. Of course she will still sell records and make money, but it will be hard to capture that personal relationship and connection with fans. Maybe she can cry again.

So why did she do it? She is reportedly worth at least $110 million. Did she not get enough money from American Idol? Is she losing a lot in her divorce? Does she really just love the Fiat? Chicago Tribune’s Phil Rosenthal seriously doubts it. He wrote, “Does anyone think Jennifer Lopez really drives her own car? Do those who believe Jennifer Lopez drives her own car, really think she drives a Fiat 500?”

Or maybe, as Francois said, Lopez just wanted to stand out. Brad Tuttle at Time magazine said, “By now, years after Britney Spears at the MTV Awards and Janet Jackson at the Super Bowl, the presence of nearly naked artists performing provocatively on stage and TV is ho-hum old news. Been there, ogled that. To get attention today, the most shocking thing you can do is insult the audience with brazenly overt marketing.”

The real question is did Lopez ignite a new trend. Whether for more money or for shock value, will artists follow in her footsteps? Are we going to see Rihanna dancing on a giant-scale model of a Kodak camera (which would still make more sense than a Fiat)?

Whatever happens, J. Lo proved one thing Sunday night—she couldn’t care less if people call her a sell out. I guess some could argue that in a way she is being “real” in her lack of shame. So by all means J. Lo, keep pretending you drive a Fiat.