A few more suggestions for
British Non-Racing Car Super Lap (550PP SM):
Jaguar XFR '10 (550PP SH) SM tires
Lotus Esprit V8 '02 (550PP SS) SM tires
I found both of these tunes capable of a gold lap. While the McLaren practically drives itself around the track, these two provide a nice bit of challenge and will keep you from feeling too smug if you're of middling skill and are starting to think you're getting to be very good.
In the original posts
shaunm80 refers to the Lotus as a "wild child" and the Jaguar as "a bull who has eaten too much chilli powder for lunch". Both are accurate descriptions of the tunes, but as I just came off of testing a few TVRs at the same track, I might venture to say they aren't all that crazy. It's like when someone says, "My mom is crazy." and you're like "Yeah, my mom is crazy too, she does some silly things sometimes." and they're like, "No. My mom is in prison.", and you're just like, "Oh..."