I made use of the Solutions by
https://www.trueachievements.com/SemtexDrinker.htm, so following in the same vein, complete the checklist of cars to get the achievement:
1969 Ferrari Dino 246 GT [62,500cr - Level 24]
1964 Ferrari 250 GTO [127,500cr - Level 24]
1994 Ferrari F355 Berlinetta [131,000cr - Level 23]
1999 Ferrari 360 Modena [133,500cr - Level 22]
1991 Ferrari 512 TR [144,000cr - Level 22]
2005 Ferrari 612 Scaglietti [158,000cr - Level 22]
2002 Ferrari 575M Maranello [165,000cr - Level 22]
2004 Ferrari F430 [174,000cr - Level 23]
1984 Ferrari GTO [197,500cr - Level 36]
1987 Ferrari F40 [230,000cr - Level 36]
1967 Ferrari 330 P4 [235,500cr - Manufacturer Club Races: Club della Scuderia Ferrari]
1995 Ferrari F50 [249,500cr - Level 36]
2002 Ferrari Enzo Ferrari [250,000cr - Level 36]
1998 Ferrari F355 Challenge [206,000cr - Level 30]
2006 Ferrari #62 Risi Competizione F430GT [300,000cr - Factory Spec Races, Ferrari F430 Challenge]
2005 Ferrari #11 Larbre Competition 550 Maranello GTS [325,000cr - Level 46]
2003 Ferrari #72 Team Alphand Aventure 550 Maranello GTS [325,000cr - Level 46]
2003 Ferrari #88 Veloqx / Prodrive Racing 550 Maranello [325,000cr - Level 46]
1998 Ferrari #12 Risi Competizion F333 SP [350,000cr - Professional Series: Class R2 World Trophy]
2005 Lamborghini Gallardo [152,500cr]
1988 Lamborghini Countach LP5000 QV [159,500cr - Level 33]
1997 Lamborghini Diablo SV [204,500cr - Level 33]
2005 Lamborghini Murcielago [214,500cr - Level 33]
1999 Lamborghini Diablo GTR [236,000cr - Manufacturer Club Races: Club del Toro Furioso]
2006 Maserati GranSport [96,500cr]
2005 Maserati #15 JMB Racing MC12 [325,000cr - Endurance Races: Mugello Supercar Grand Prix]
2005 Maserati #35 Risi Competizione MC12 [325,000cr - Semi Pro - Risi Competizione 600 HP]
2004 Maserati MC12 [250,000cr - Regional Championships: Italian Masters Championship]
2005 Maserati #9 Vitaphone Racing Team MC12 [325,000cr - Professional Series: Class R3 World Trophy]
1992 Lancia Delta Integrale EVO [37,500cr - Proving Grounds: RWD Shootout]
1974 Lancia Stratos HF Stradale [73,000cr - Level 10 in Europe]
1999 Pagani Zonda C12 [214,000cr - Level 38]
2003 Pagani #17 Carsport America Zonda GR [325,000cr - Rivalry Face-offs: Pride of Italy]
I found the auction house to be the best place to get cars that you haven't yet unlocked. Be patient and you can often get them below the prices listed at the dealership.