A method of in-vehicle presence detection comprising: detecting, by a first mobile device (110; 1010), a signal having a characteristic of an in-vehicle detection system; detecting, by a second device, the signal, the signal including content that is unique within a time space of an offset between the first mobile device (110; 1010) and the second device, wherein the second device is a second mobile device or is a vehicle mounted device, and characterized in that the content is a random selected sequence of a predetermined byte length or a counter value that is unique within a latency of an arrival time between the first mobile device and the second device; in response to respectively detecting, by the first mobile device and by the second device, the signal, transmitting, by the first mobile device (110; 1010) and the second device, a first indication and a second indication to a cloud solution (130; 1030), wherein the first indication and the second indication represent respective detections of the signal having the characteristic of the in-vehicle detection system; receiving, by the first mobile device (110; 1010), a first instruction from the cloud solution (130; 1030) to analyze one or more first sensor signals to determine a first event; receiving, by the second device, a second instruction from the cloud solution (130; 1030) to analyze one or more second sensor signals to determine a second event; transmitting, by the first mobile device (110; 1010), first information reflecting the first event and its respective first timing based on a first clock of the first mobile device (110; 1010); transmitting, by the second device, second information reflecting the second event and its respective second timing based on a second clock of the second device; cross-correlating, by the cloud solution (130; 1030), the first event, the second event, the first timing, the second timing and the content to generate an indication of in-vehicle presence. detecting, by a first mobile device (110; 1010), a signal having a characteristic of an in-vehicle detection system; detecting, by a second device, the signal, the signal including content that is unique within a time space of an offset between the first mobile device (110; 1010) and the second device, wherein the second device is a second mobile device or is a vehicle mounted device, and characterized in that the content is a random selected sequence of a predetermined byte length or a counter value that is unique within a latency of an arrival time between the first mobile device and the second device; in response to respectively detecting, by the first mobile device and by the second device, the signal, transmitting, by the first mobile device (110; 1010) and the second device, a first indication and a second indication to a cloud solution (130; 1030), wherein the first indication and the second indication represent respective detections of the signal having the characteristic of the in-vehicle detection system; receiving, by the first mobile device (110; 1010), a first instruction from the cloud solution (130; 1030) to analyze one or more first sensor signals to determine a first event; receiving, by the second device, a second instruction from the cloud solution (130; 1030) to analyze one or more second sensor signals to determine a second event; transmitting, by the first mobile device (110; 1010), first information reflecting the first event and its respective first timing based on a first clock of the first mobile device (110; 1010); transmitting, by the second device, second information reflecting the second event and its respective second timing based on a second clock of the second device; cross-correlating, by the cloud solution (130; 1030), the first event, the second event, the first timing, the second timing and the content to generate an indication of in-vehicle presence.