These modifications were also incorporated on the race cars albeit with the addition of a fixed rear wing instead of a ducktail spoiler.
ðiːz mˌɑːdɪfɪkˈeɪʃənz wɜːɹ ˈɔːlsoʊ ɪŋkˈoːɹpɚɹˌeɪɾᵻd ɔnðə ɹˈeɪs kˈɑːɹz ɔːlbˈiːɪt wɪððɪ ɐdˈɪʃən əvə fˈɪkst ɹˈɪɹ wˈɪŋ ɪnstˈɛd əvə dˈʌkteɪl spˈɔɪlɚ.