Performance sedans

What is your definition of "affordable?" 20K? 25K? 40K? An Infinity Q50 Red Sport 400 is pretty sporty and powerful, but will set you back quite a bit more than a Taurus SHO. Set a price then see what models offer the most for that price.

Hard to beat a Honda Civic & Accord for all the above including not mentioned reliability. Toyota Camry or the Corolla, Nissian Altima, Nissan Sentra, Hyundia Sonata, Hyundai Elantra, Kia & Lexus (basically a Toyota) are very Good choices as-well as the Acura ILX which is basically a Honda Civic with different taste. Performance also means it performs and not in the shop all the time. Most others are shop magnets. Stay away from Cadilac, Alfa, VW, Audi, Subaru, Mercedes, Chrysler, Dodge cars trucks are o.k., Lincoln, Jaguar, Infinity they are not worth the Money and loose value too fast and cost too much to fix, Although I really want to throw Buick, GM, & Ford in this too as stay away too, but only half hearted because there is a few that are fine but still loose value faster. If your budget permits more money a higher end BMW is the only way to go in a sedan. Otherwise all the other I listed at top of my answer is a better choice even over the BMW, as they cost alot to fix if it does ever need it and base models are at least 10 grand more than those above. A higher optioned model with the sports package and or luxury package (including leather) and all options on one of those in first part of message is a better deal any day and also increases your resale value higher than a BMW unless sold by age 3. Those would be what I call affordable.

He wants a sporty sedan, ruling out most of the Toyotas, Nissans, Hyundais, and Kias mentioned. A Civic Si would be a good choice, as would an Acura TLX.

Sorry, I meant TSX. The current Acura line-up is a a collection of afterthoughts and also-rans.

I really like the new Civic's, My niece bought one and is happy. The customizing you can do with them is off the charts. A wide body kit TSX below.

Honda civic type r in 4 door. Civic's also comes in 2 door.

Click on picture to maximize.