A 4 lug pattern to 5 lug pattern adapter will be a minimum of 35mm thick as it has to be a two piece unit.
Also, you'll likely have to change out your wheel studs to shorter units, because the stock ones could come into contact with the outer piece of the adapter.
Adaptec Speedware can do it, but plan to give them ~$400.
What BMW/Chevy wheels are you trying to fit? Most don't exactly have favorable offsets for a focus because they are set up for RWD not FWD.
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