I post very little on here but this is worth writing.
many owners of pt or performance street cars put a harness system in their car because it looks right or it gives the look they are wanting.But mounting of this system is more critical and if done wrong can hurt you more than no seat belt at all.pay close attention to what they talk about and how the harness is mounted.A cage is not an option if you are serious about driving hard whether on a twisty road of the track.
And cage design is also critical.If you design it for just ease of entry or exit and don't look at the protection till after, the outcome of an incedent could be serious.
This is what myself and a nav walked away from doing close to 160.Stan