I finally took some time to do a few of the challenges (I forget their exact names...) and unlocked the track I was most hoping to unlock - The Top Gear Test Track. That was pretty fun! I finally got the feel of driving and drafting those buses, and it wasn't too bad. Initially - I was pretty frustrated, but then figured out a strategy. I tried the Lotus, but wasn't feeling it, because I got distracted by seeing a '87 GNX (I think it was an "X") for sale, so I scooped that up. Then I noticed a C4 ZR-1, but missed that one

I did find a C4 GS, and got that one. Finally, I picked up an '01 SS. I did find the Silverado Concept Truck, too. That thing drives like poop, but I haven't finished mod'ing it because I was low on dough, and had to drive in order to earn credits to buy all these cars. I'll have to keep my eyes open for that ZR-1 though
I played for a few hours last night and had an okay time. I kinda' like finding those older cars; that's some motivation for me.
Another thing I don't really like is I guess you can't remove and of the mod's on the cars. I really didn't get as good a payoff with buying a second SS so I could race-modify it, but it looks okay. I don't know if I want to spend the time to do the same with my ZR1, but I probably will.
I do like rebuilding the engine and chassis features though. They cost a lot of credits, but that's pretty cool. I wish we could modify the "Standard" cars more though, because I was hoping to at least get some wheels for the SS. The only thing I ended up doing was painting it. I didn't have much money for the other mods', but I was hoping for a body kit, or a nice spoiler or wheels, but - Oh well!
I'm also finally getting a little more used to modulating the throttle and brakes, too. I was able to control my '10 SS around Laguna Seca and get into the lower 1:20s. I think I actually have it tuned better than my ZR1, lol.