Hola he visto esto y no se si serviria para un a4 2011, pre-restyling, con mmi 3g hdd ?
https://es.aliexpress.com/store/product/Camera-Interface-with-Dynamic-Parking-Guideline-IPAS-Carplay-Box-for-A4-A4L-A5-S5-Q5-Original/1958659_32828570604.html?spm=a219c.search0104.3.74.63fa7ed9YJxhrQ&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_318_319_10548_10696_450_10084_10083_10618_452_535_534_533_10307_532_10301_10821_204_10059_10884_10887_100031_320_10103_5727015_448_449_5727515,searchweb201603_60,ppcSwitch_0&algo_expid=3e41f775-27a2-4fa3-ac12-97eb0f954ff8-10&algo_pvid=3e41f775-27a2-4fa3-ac12-97eb0f954ff8&transAbTest=ae803_5
Y si funciona, saber si es muy dificil instalarlo