Will GTA 6 have car customization?
The direct answer
Yes. Multiple mod shops are confirmed, so vehicle customization returns.
Rockstar has named mod shops including Rideout Customs in Vice City and One-Eyed Willie’s on Lake Leonida, confirming vehicle customization as a feature.
The full upgrade system — visual and performance mods — hasn’t been detailed, but customization is clearly returning in the Los Santos Customs tradition.