Assuming the paint work is not bad try this.
Two coats then your wax of choice.
The secret is in the preparation though.
pressure wash with APC
remove decontamination (iron and tar) - try TRIX
rinse and or snow foam again
cleanse with IPA
wax glaze - 2 coats
use a sealant C1+ and C1.5 (two coats of the later)
wax - 2 coats.
Interior and glass - yet more work.
Two or three days later a gleaming car just needing a wash or a snow foam when dirty for 6 months.