GT3 packs

My steam inventory shows that I have all of the GT3 cars so what is different in the challenge pack and endurance pack ?

 

They both have 5 cars, but the Endurance pack has no GT3 cars.

The Endurance pack has
Oreca 07 LMP2
Norma M30 LMP3
Corvette C7.R GTE
BMW M8 GTE
Porsche 911 RSR GTE

The Challengers pack has
McLaren 720S GT3
Audi R8 GT3
Porsche 911 GT3
BMW M6 GT3
Aston Martin Vantage GT3

 

Endurance Pack has GTE, Challenger Pack has GT3.

GT3 and GTE are different classes.

 

Which pack has the Bentley continental and the SLS AMG.?

Also, I am looking for a list of RF2 “official” content, both ISI and Studio 397, cars and track.

 

The GT3 Pack - https://store.steampowered.com/itemstore/365960/detail/1001/

This is all of all store items: https://store.steampowered.com/itemstore/365960/browse/

Here is a list of S397 official free content: https://steamcommunity.com/id/studio-397/myworkshopfiles/?appid=365960
and here is ISI: https://steamcommunity.com/id/ImageSpaceIncorporated/myworkshopfiles/?appid=365960