Audi A4 upgrades, generation by generation.

The B8 and B9 in roughly equal numbers. B8 owners come for the CarPlay box on MMI 3G; B9 owners for activation of the smartphone interface, the Android screen on 2016–2019 cars, cameras and dash cams. B7 cars come in for an Android screen because the Concert radio has no usable display.

Only in the routing. The rear dash cam cable runs along the tailgate loom through the factory grommet, so it survives the tailgate opening. For a subwoofer the Avant takes a slim enclosure under the boot floor or an under-seat woofer on the B9, so the load area stays flat; the saloon uses the same enclosure on the boot floor.

B7 — 2004–2008 (saloon, Avant and cabriolet): Concert, Chorus or Symphony radio in a double-DIN slot, RNS-E navigation optional; Bose on some cars. B8 — 2008–2015 (saloon, Avant and allroad): Concert or Symphony radio with a 6.5-inch screen, MMI 3G navigation optional, 3G+ from the 2012 facelift; Bang & Olufsen optional. B9 — 2015–2024 (saloon, Avant and allroad): MMI radio plus with a 7-inch screen or MMI navigation plus on MIB2 with 8.3 inches to 2019; MIB3 with a 10.1-inch touchscreen from the 2019 facelift; Audi smartphone interface optional, standard on later cars. Not sure? Send the reg on WhatsApp and we tell you the generation and the route.

CarPlay: Activation on MIB2 B9 cars, a CarPlay box on the B8's MMI 3G screen, an Android screen on the B7. Car radio: Android screen in the B7's double-DIN slot, or with the MMI knob kept on the B8 and B9. Reversing camera: Camera coded into the MMI on the B9, through a box or interface on the B8, on the screen on the B7. Parking sensors: Four sensors in the rear bumper with a buzzer that beeps faster; sound only. Ambient lighting: Ambient LED kits on the B7 and B8, extended ambient lighting on the B9. Dash cam: Hardwired from the driver's side fuse panel with a low-voltage cut-off. Subwoofer: Under-seat woofer or slim boot enclosure on a DSP amplifier; the Avant floor stays usable. Speakers: Plug-in door speakers on every generation; Bose and Bang & Olufsen amplifiers stay. Soundproofing: Doors and floor treated with butyl and foam, trim refitted without marks.

CarPlay: under an hour for activation, two to four hours for a box or a screen. Car radio: two to three hours, usually the same day. Reversing camera: two to three hours. Parking sensors: two to three hours. Most A4 owners wait at the workshop or drop the car in the morning and collect it the same day.

B7: the Concert, Chorus or Symphony radio in a double-DIN slot, RNS-E navigation optional; Bose on some cars stays and we add to it. B8: the Concert or Symphony radio with a 6.5-inch screen, MMI 3G navigation optional, 3G+ from the 2012 facelift; Bang & Olufsen optional stays and we add to it. B9: the MMI radio plus with a 7-inch screen or MMI navigation plus on MIB2 with 8.3 inches to 2019; MIB3 with a 10.1-inch touchscreen from the 2019 facelift; Audi smartphone interface optional, standard on later cars stays and we add to it. Steering-wheel buttons, factory amplifiers and cameras are carried over on every route; the only route that changes what you see is an Android screen, and even then the controls are kept.

Send the reg or the year on WhatsApp or the form below and we confirm the generation, the route, the price and the next free slot. Every job carries a one-year warranty on the work, done at our workshop in Rosemount Business Park, Dublin 11, Monday to Saturday.