I haven't been on the forums for a while, or even Forza 2. Unfortunately, Forza 2 freezes every time I start a race. I downloaded the demo, and even that freezes(??). I decided that maybe I had too many cars (Note: It probably wasn't this, but I've got nothing else to try). Also, Forza 3 is coming out soon, and I just like giving :). So, in an attempt to fix this, I'm giving away 20+ cars!!
Here's the list:
D-Class:
-1974 Lancia Stratos HF Stradale (D400) -- [Grarghsies]
C-Class:
-2001 Mazda Familia
B-Class:
-2008 Maserati GranTurismo -- [Grarghsies]
-2006 Proto Motors Spirra -- [Cheeze18]
-2007 Nissan 350Z GTC (DLC) -- [ddabb808]
A-Class:
-1994 Ferrari F355 Berlinetta (A850) -- [BIGxM1KE]
-2005 BMW M3 E46 (A850 / Tune) -- [Mugen NSX RR]
-2001 Mazda Roadster (A850 / Kind of tuned / X2)
-2008 BMW M3 E92 (A850 / *DLC* / x2)
-2004 Mazda RX-8 (A850) -- [fleron230]
-2002 Lotus Esprit (A850)
-2007 Jaguar XK Coupe (A850)
-2007 Audi S5 (A850 / DLC)
-2002 BMW M3-GTR (A850) -- [UnderTheKnif3]
-2006 Volkswagen Golf GTI (A850) -- [fleron230]
-1967 Lamborghini Miura P400 (A850 / DLC)
-1967 Shelby Cobra 427 S/C -- [XuivekaX]
S-Class:
-1998 Ferrari F355 Challenge (S998) -- [BIGxM1KE]
-1995 Ferrari F50 (S998) -- [Gifted]
-2005 Ford GT (S998) -- [JoaoJose]
-1987 Ferrari F40 (S998) -- [UnderTheKnif3]
-2002 Ferrari 575M Maranello (S998) -- [JamnMag]
-1984 Ferrari GTO (S998 / x2) -- [j town boy 2] / [GRAV35]
-1997 Lamborghini Diablo SV (x2) -- [j town boy 2] / [REDvsBLUE2008]
-2003 Volkswagen Golf R32 -- [Cheeze18]
-2002 Koenigsegg CC8S -- [JoaoJose]
-1993 Jaguar XJ220
-2003 Porsche Carrera GT -- [XuivekaX]
U-Class: [All Gifted]
None Yet...
R4-Class:
-2003 Dodge #23 Magellan Financial Viper Competition Coupe
-2004 Ford #10 Tiger Racing Mustang (x2)
R3-Class:
-2001 Dodge #58 Larbre Compétition Viper GTS-R
-2006 Panoz #81 Team LNT Esperante GTLM
If you want one, just post a request, I'll send you a friend request, then gift you your car.
Update: Still posting more. All the cars that have tunes are indicated. They aren't professional tunes, just my personal tunes meant to keep me off the dirt and grass. 
I've decided just to start over. I'll send all my cars and money to my new save as soon as I gift these cars. Then, hopefully, I can play.
Another Update: I started over and that didn't work. I'm going to buy another disc today...
And another Update: The 3rd disc didn't work. Oh well...
An optimistic Update: I figured out it is my HDD. It runs like quicksilver (Hg) without the hard drive. I've always wanted to use that simile... 
A contradicting Update: It's actually my Xbox. It can't write information. I'll buy an arcade or something. No big deal, my other one lasted for 3 1/2 years, and maybe my friend will give me one of his 3...