If they're originally made in the uk (EU) then potentially, no.
https://www.gov.uk/guidance/rules-of-origin
New and from the US, yes.
With an import of UK sourced stuff a couple of years ago, HMRC have applied a 12 month limit on export with UK origin stuff we've re-imported. i.e. if something was exported more than 12 months ago, then duty/VAT was still payable on import.
In general, my experience of importing small quantities of new and secondhand car bits from the US over the last 15 years has been that it's a complete lottery as to what (if anything) you get charged in duty and/or VAT when it comes into the UK.
You need a carnet this proves it was imported then re-exported
In general, my experience of importing small quantities of new and secondhand car bits from the US over the last 15 years has been that it's a complete lottery as to what (if anything) you get charged in duty and/or VAT when it comes into the UK.