I am sorry if yet another antenna question annoys you a little more but I have no concerns for WiFi and GSM module from your previous explanations with new antenna connectors and, in fact, they seem like not only good but the best solution for this.

I am however slightly concerned about the FM-transmitter; in every situation I find myself using it I find the range to be pretty poor (i.e. holding my hand up awkwardly in a friends car if the antenna of said vehicle is on the back). As I seem to recall (only seem) that the FM-transmitter antenna has no conector for easy replacement I would be rather disappointed if the case would act as a little "Faraday cage", if you will, and further reduce/cripple the range even more.

Thank you for the great work and keep it up, it sure sounds promising, I hope in the following weeks I can say it looks promising . I just hope I have not asked something silly