Standard entertainment in many top-tier 2003 models.

To give you the most relevant "useful feature," could you clarify if you mean: A feature available on a specific 2003 model? A maintenance feature from a dealership (like Auto Haus)? The Infiniti G35 Is The Best $5000 Car In The World

Improved traction control for automatic transmissions.

Available in premium models like the Infiniti G35.

Based on the 2003 automotive context, a highly useful feature—often highlighted in retro reviews or 2003-era vehicle comparisons—is .

Enhanced driver comfort for luxury vehicles.