As one important characteristic of an intelligent product is its ability to evolve, system updates have become vital for its success. In addition, a good perception of system updates may improve users’ positive attitudes toward the product and encourage continuous usage. However, how to enhance such perception remains largely under-explored. This study investigated how different visualizations of steering performance improvement can influence people's perception of autonomous vehicles. We measured 120 people's responses to three different types of visualizing methods. The results showed that the line charts were most effective in increasing the perceived improvement of updates, which could further promote users’ satisfaction, purchase, and recommendation intentions. We further discussed how our findings could help design future visualization of system updates.