Piper Jaffray analyst Alexander E. Potter has been mostly silent on Tesla since last summer.

He says he spent the last seven months driving a Tesla, and after getting a feel for the car, meeting with the company's management team, and crunching the numbers, Potter upgraded Tesla's stock from "Neutral" to "Overweight" and upped his price target from $223 to $368.That's about 18% above its current stock price.

In a note sent out to clients on Monday, Potter says that "even with all the risks, we think growth investors can't afford to ignore this stock."

Potter thinks Tesla is not like other companies and is given a big valuation and forgiven for mistakes because it evokes real emotions in people such as, "optimism, freedom, defiance." The company has an almost cult-like following that makes it difficult for analysts to cover, which Potter thinks this is a good thing for Tesla investors overall, noting:

Tesla's stock price is up about 46% so far in 2017.

Click here for a real-time Tesla chart.