One problem related to cruise control has been reported for the 2005 Infiniti Q45. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Infiniti Q45 based on all problems reported for the 2005 Q45.
When cruise control is set, and the need to pass or speed up is required, if you press the gas pedal to the floor the car takes off and *then stops responding and drops back to set cruise control speed while you are still flooring it. It bucks back and forth. I spoke to several owners on a Infiniti owners site and theres performs the same. Its dangerous if the need to speed up occurs. This is a problem in the coding of the parameters in the ecu and could be deadly with unexpected performance. This happened on i40 in knoxville tennessee in heavy traffic. This condition can be repeated back to back multiple times.