ðæt ɪz wˌaɪ fɔːɹ nˈaɪntiːnhˈʌndɹɪd nˈaɪnti ˈeɪt, ðɪ ˈɑːɹ θɹˈiːhˈʌndɹɪd nˈaɪnti wʌz mˈɑːdᵻfˌaɪd, mˈoʊst nˈoʊɾəbli ɪnðɪ ɛkstˈɛnʃən ʌv ɪts ɹˈɪɹ bˈɑːdiwˌɜːk tə kɹiːˈeɪt ɪŋkɹˈiːst "lˈʌɡɪdʒ spˈeɪs" ɪn ˈɔːɹdɚ tə sˈæɾɪsfˌaɪ ðɪ ˌeɪsˌiːˈoʊ, ɐ nˈuː ɹˈɪɹ wˈɪŋ fɔːɹ ɹˈeɪsɪŋ mˈɑːdəlz ðə ɹˈoʊd lˈiːɡəl vˈɜːʒən hæd nˈoʊ wˈɪŋ, ænd ɐ ɹˈɪɹ dᵻfjˈuːsɚ fɔːɹ ɪmpɹˈuːvd dˈaʊnfoːɹs wɜːɹ ˈædᵻd.
That is why for 1998, the R390 was modified, most notably in the extension of its rear bodywork to create increased "luggage space" in order to satisfy the ACO, a new rear wing for racing models (the road legal version had no wing), and a rear diffuser for improved downforce were added.