My suggestion would be to be honest about your budget for this. Add up your payments, insurance, estimated repair costs and gas. You're specifically asking about repair costs - off the top of my head, $2000-$2500 a year would seem reasonable rule of thumb for most of the vehicles you mention, probably a little more if its a turbo; a little less for the Fiat maybe? More if you're putting on crazy miles; less if you're not. Price out the cost of a third party insurance policy for repairs (pay attention to what they exclude), and you'll see what the bean counters think the cost of repairs will be for the car. So if you're looking over a five year time horizon, you'd probably spend $10-12.5k on repair and maintenance.
Also figure out your risk tolerance for a big repair bill. If you're driving a 100k+ Audi, the engine may die on you. Will you have the cash to buy a used engine or transmission and pay someone to put it in? Check car-parts dot com for used prices in your area. Alsogo to the users website for whatever model you're considering and see what the common problems with them are, and how expensive the fixes are.
If you were in NY and spent $20k/5 years on one of the cars you mention and drive it 10k miles a year, you'd probably be looking at $4.5k payments, $2k repairs, $2.5k insurance, and $1.1k gas, so $10.1k a year in automotive expenses. Or, assuming your repairs/maintenance would run somewhere between $500 (no repairs) - $9,000 (a major and a minor repair or two in a year), your costs could be $8.6k - 17.1k. Your Honda, assuming it's paid off, is costing you on the order of .5k depreciation, $1k repairs, $1k insurance (no collision), $1k gas, so $3.5k a year. I'm making assumptions here, but adjust for your specific case.
Even assuming you've got that $10.1k a year in cash flow coming in that you could spend on a car, my suggestion is you'd be better off slugging it out with the Accord and banking that extra $6.6k a year. In a few years you could pay cash for something really cool.
Of course you could go a middle of the road option; get a $3k-5k Miata, a Lexus SC or IS300 or something like that; give yourself more like $4-5k automotive expenses. I'm sure if you think hard about it and consider what you really want out of a car, you can find a $5k car you like that you can keep on the road for $1k a year in repairs and maintenance.