Passenger, lovefab Turbo NSX.
Driven, lovefab Turbo Civic (450 whp).

Favorite car ever driven, my miata.

Ariel Atom. 300hp K20.

Honorable Mention

500whp LS1 FD RX7
250whp Tripoint Elise
996 GT3

All ridden in, never driven. Atom was amazing, but I prefer the Elise. Atom is just too unpractical as a street car.

The fastest I can think of might have been a VR4 Galant pumping something like +20 lbs.

Ridden: Lotus 7 with 265hp
Driven: My old Talon with 320hp

ridden: supercup 996
driven: dual t-66 502 in a tube framed cutlass with a 3-speed that left off the trans brake. It was fun.

Formula Continentals and Formula Fords. Not the fastest cars in the world in a straight line (still fast though), but in a turn simply unbelievable. I have driven through the kink (a really fast turn) at Road America flat footed at around 130 MPH.

:dunno: probably my boss's 996TT

Ridden: the 616rwhp yellow Miata or Dads pro-street style 1930 Model A (high 8's 1/4 on street tires!)

Driven: hmm I don't really remember

Fastest car I've ridden in and driven fast is a Lambo Gallardo. I once got a lap in a Lotus 70, but I was so afraid to fuck up I babied it.

Ridden:
Buddy's 01 Procharged SS making ~600 HP...high 9 second FULL street car. Beat the piss out of a Gixxer 750 w/ NOS was prolly the best kill...still not the fastest car I've seen around though by any means.

OR...

My other friends 05 STi making 650awhp/650awtq + 150 shot.
AWD burnout on launch...spin 2nd...3rd....chirp 4th...

Hennessey viper was the fastest I have ever been in, and fastest that I have driven is a 76mm turbo ls1 camaro.

passenger: '76 corvette that ran low 10s all motor (street legal, but probably shouldn't have been). A friend bought it, and decided the suspension was crap. He paid an engineering company to design tubular suspension bits, custom springs/dampers and all for road track and autoX use. The thing was absolutely insane.

driver: same. owner - "come on... give it a little juice"
me - "I think you clutch is slipping"
owner - "look in the rear view"
me - "it's wrong that there is that much tire smoke at 140 mph"

After that drive the owner determined it was wise to de-tune the car some... so we limited the carbs (dual 4 barrels) to only 50% open at WOT. The car still ran low 12s with the "governor" we installed.

Driven:
'02 Benz C36.. to the floor all the way to the 155mph limiter, several times... gotta love the Nevada desert.

Ridden:
'02ish Superformance Cobra w/aluminum smallblock. 500whp or so, he said like 2100lbs. Made for interesting onramps. I found as a passenger that my brain and eyes simply could not keep up. He was looking and thinking so far down the freeway where his next move would be that I was terrified the entire ride and don't remember much. It was so loud and brutal I think I might pass if I was ever offered a ride/drive one on the street again... at least at that performance level.

I might have everyone beat here for fastest top speed in a "vehicle" though. I think I may have hit 800kts in a Tomcat over Nevada, but I KNOW I was over 700kts in a Viper... from the backseat of course, where it's safe.

I have a 1200whp Chevelle to drive once I sort the fueling. Its gonna ruin me.

fastest cars
mercedes SL65 on street
mercedes SLR on pocono

That was a good day, seeing a yellow miata streak past sonic at over a 100, in rush hour hillsborough ave traffic

Passenger in a lingenfelter Corvette C5. At 90 mph on the highway flooring it makes the tires spin and pull sideways.

fastest passager would be maybe a buddies 1gen AWD DSM laying 4 drags in 2nd gear from a roll.... second would be R32 GTR skyline....the looks that gets you street side... and in South GA its even better

fastest I drove would be my old DSM w/ 300whp or my 02 R6 with a 60 tooth rear sprocket....I could stand 6th gear up from a roll....no top end but one hella stunt bike lol

passenger: Ruf ctr2 at Hockenheim, we hit 183mph
driven: my 96 Talon AWD, 150+mph in Germany.

i'm jealous of a lot of these posts. I have no friends into cars and I'm poor so no fast rides for me. Once though a couple years ago I got a ride in a rousche mustang from an ex-girlfriends brother. Not as fast as some posted here but it was enough to pin me in my seat and have respect for domestic cars after that. At ~160mph on a Florida country road all I could think of was that I was going to die if anything happened.