– What do you need for this (CanBus adapters?) and what do you have to consider? – Who has useful tips and tricks regarding the installation of cables (power cables, speaker cables)? – How complicated is it to install a roof antenna and to install the antenna cable (vehicle has head airbag)? The previous concept includes a partially active 3 way front system controlled via a 4-channel power amplifier and a Sony GT 700. HU is already available, for example speaker and power stage you are welcome Post suggestions or recommendations. But if together the pain limit of 700€ should not exceed and definitely be new. As a power amplifier I have so far considered an Eton EC 500.4., loudspeakers I have thought of so far only a 10er 2-way system (possibly Eton or Rainbow) and a 20er (evtl Hertz). A subwoofer is not intended for the time being, but will possibly be retrofitted at a later time. MfG.