Chinese Tesla rival launches $22,000 EV with self-driving features. Here's why that's a big problem for Tesla.

• Chinese EV maker Xpeng just launched a new low-priced EV.
• The cheapest version of this car is nearly half the price of Tesla's Model 3 in China.
• Elon Musk's car company faces stiff competition in China from a wave of cheap, tech-heavy local EVs.

One of Tesla's Chinese rivals just launched its new low-priced EV with self-driving tech — and it shows just how big a challenge Elon Musk faces in staying competitive in the world's largest EV market.