I've listened to several speaker lines, most of which didn't do much for me. Of those I've heard (in showrooms), the Focal V.Slim and a Dynaudio component set (sorry, don't recall the model#) were best/most versatile. Also have listened to various MB Quart, Alpine, A/D/S, Morel, Pioneer, JL Audio. I'd really like to listen to the Polk SR6500 and BA 6.5 sets, but I've found the dealer listings on the mfr sites are incredibly inaccurate (what's the matter with these guys? don't they want to sell speakers?).
Now I realize an open roadster is not the ideal listening environment for subtlety, but I want some speakers that are reasonably good and mate well with my amp. I'm going to be Dynamatting the doors, and would like decent mid-bass. I should add that I'm going to add some S-Pods (speaker enclosures that attach to the roll bar and take 5.25" components) for high-speed fill. I'm not considering a trunk-mounted sub yet, and won't do so until I've optimized the cabin.
Budget? Maybe $500-$600 for the 6.5 components, and much less ($100?) for the S-Pod speakers.