Nissan could have bought a stake in Aston Martin as early as 2012

Three unnamed company insiders told Reuters that Palmer made attempts to convince Renault-Nissan CEO Carlos Ghosn in 2012 and 2013 to invest in Aston Martin, but his proposals were shot down both times for unspecified reasons, according to Automotive News. "We looked carefully at the proposal but we passed on it," said one of the sources.
You can easily see why Palmer was eying Aston Martin even back in 2012. It's no secret that the British sports car mavens were in need of extra funding, well before the Daimler investment. Building vehicles these days is only getting more expensive with stronger safety and emissions requirements. Just look at the brand's desperate hope to get a side-impact crash exemption to keep selling its models in the US as an example.
Still, It's fun to imagine automotive history going a very different way than it has. Think of the possibility of Aston Martin models using Nissan V8s or even the turbo V6 from the GT-R, but wrapped in the British brand's svelte styling, or that the rumors of Mercedes and AM possibly sharing platforms in the future were instead with Infiniti or Renault. Source