Based on Bill's skills, experience, and location, I estimate his hourly rate to be around $125. Considering his expertise in development, design, and product development, and his experience in automotive and engineering, he likely falls within the mid-range of the national average for professionals in these fields. According to the Bureau of Labor Statistics, the median annual salary for software developers in the Detroit-Warren-Dearborn, MI Metropolitan Division is around $94,000, which translates to approximately $45-$60 per hour. However, Bill's experience and skills suggest he could command a higher rate, around $125 per hour, considering the value he brings to clients.