These coil pack adapters let you use newer and cheaper R8/FSI/TSI ignition coil packs. I used 06E905115E which can be had for $18 per coil. This should fit VW MK4 and Audi MKI 1.8t engines.

On the older style valve cover with the factory bolt down coils, the newer coils will sit slightly off center. The pricey centered aluminum coil pack adapters can put stress on the components which could lead to premature failure. They also tend to not cover the entire coil well, which allows debris and moisture to fall into the spark plug hole. Without the adapters, engine vibrations can cause the coils to pop off the spark plug or possibly fail due to stress.

These are modeled after the Hitachi 06B905115E coils, with predefined mounting angles from the OE 077905390 plastic adapter.

Suggested files to print:
angled_solid.stl - Early Model Year valve covers (eg. AEB, AGU, AWD) with factory bolt down coils and coil wells
centered_solid_trimmed.stl - Late Model Year valve covers (eg. AUQ, AWW, AWP) with factory push down coils

If you want to go all out, you can send the optimized STEP file to a machine shop to have milled out of aluminum.

Print the coil pack adapters with a high temperature filament (such as nylon or polycarbonate), upside down, with supports in the center. Use at least three perimeters. If you wish to retain the vacuum reservoir or you can't be bothered to move it, print three of the reservoir retention standoffs. Press the compression limiters into the 3D printed adapters and standoffs using a vise. Install the adapter on the coil first, and then push them onto the spark plug. Torque the bolts to spec. After installation, drive around until the engine is up to temperature and then re-torque the adapter bolts.

You can purchase the ignition coil seal for improved moisture protection, but is not necessary. Factory bolt down coils don't come with them anyways.

Printing in PETG or PLA is ill-advised. The valve cover sees around 190°F which is close to or past their glass transition temperature. ABS appears to crack due to heat cycling.

Tightening torques:
• Ignition coil to cylinder head cover 10 Nm (7 ft-Ib)

M6-1mm x 30mm Socket Head Screw:
https://www.mcmaster.com/95263A576/

Compression Limiters:
https://www.mcmaster.com/91868A429/

Ignition Coil (07K905715G):
https://www.rockauto.com/en/parts/bosch,0221604115,ignition+coil,7060

Optional Ignition Coil Seal (058905261A):
https://www.fcpeuro.com/products/audi-vw-ignition-coil-seal-elring-058905261a

You can find source files on my github as well:
https://github.com/XDleader555/cad_models/raw/main/vw_audi_1.8t_coil_pack_adapter