JVT, noted your tire search which also piqued my interest in comparing my current Kuhmo Ecsta 712 to other ultra high performance tires. First note, don't think the RE 950 falls in that category...the 400 wear rating should tell you that. But with my own autocross, dry handling interest in mind I noted the numerous tests Tire Rack has done with 2000 BMW 328Ci and conveniently the 225/50-16 size unless otherwise specified below. Compiled test times below on their 1/3 mile course. Times are listed from fastest to slowest. Note that asterisks are included next to each tire that identify which other tires they were tested with:

Potenza S-02.....30.75 (225/45-17,8" wide)
Michelin Pilot Sport...30.76 (225/45-17)
PZero Rosso Asimmetrico..30.78 (225/45-17)
Potenza RE730****....30.78
Yokohama A520***....30.97
Dunlop SP Sport 8000****..30.97
BFG Comp TA ZR****....31.01
Potenza S-03**..31.12(225/45-17 on 8")
Kuhmo Ecsta 712***...31.25
PZero Rosso Asimmetrico**..31.26(225/45-17)
Sumitomo HTR Z***....31.29
Michelin Pilot Sport**..31.42(225/45-17)
Potenza RE950*........31.44
Michelin Pilot XGT H4*..31.63
BFG Comp TA HR4-2*......32.05

The Yoko A520 looks like a bargain at $90 for 225/50ZR-16 and $110 for 215/40ZR-17, but that from an autocrosser point of view.

Here are a few tires tested on a 99 BMW 328i in 225/50-16 size:

Michelin Pilot XGT Z4****....30.97
BFG G-Force TA KDW***.......31.08
Firestone Firehawk SZ50***..31.15
Dunlop SP Sport 5000****.....31.17
Bridgestone RE-71**........31.18
Yokohama AVS Intermediate**.31.21
BFG Comp TA ZR4****.........31.33
Dunlop SP Sport 8000**....31.46
Goodyear Eagle F1*......31.74
Goodyear Eagle F1 GS***...31.85
Firestone SZ50*.....31.91
BFG Comp TA ZR-3*...32.14

Here are a few from the 99 328i on larger 17 X 8" rims and 235/40-17 tires or 225/45-17 when specified.

Pirelli PZero Asimmetrico**..30.88
Michelin Pilot Sport**.......30.93
BFG G-Force TA KD*...31.07 (225/45-17)
Bridgestone Potenza S-02**...31.14
Pilot Sport SX MXX3..31.23*(225/45-17)
PZero Asimmetrico...31.41*(225/45-17)

Or on a slower day, same car...

Yokohama AVS Sport........31.5
Bridgestone Potenza S-02..31.59
Dunlop SP Sport 9000......32.38

Fastest Contour at SZ 2002 Auto-X. 10th in PAX out of 125. CEO of FOGEY(Fast Old Guys Emasculating Young-uns), Inc. Terry Haines, Chairman, Senior V.P.s: (alphabetical)JavaContour, Jet Mech, MFE, SeicoRacing, SVTSTS, Vern Kilburn. If your not a member, yet, wait a few years. I'm not just the CEO, but I'm a member, too. Working with the rank and file to get the job done right!

Historical:
63 TVR (1K in 74), 75 TR-7 (paid cash new), 79 RX-7 (zoom,zoom), 81 RX-7GSL (autobahn-driven),82 Mustang GT (autobahn-driven), 85 Mustang GT (SE Division F Stock Solo II Champ), 86 MR-2 (3rd SE Division D Stock), 88 Civic DX (had 1st born and still owned MR2) 92 Sentra SE-R (all go and no show), 98 EO SVT Contour (FTD SZ 2002). 02 Altima 3.5SE 5 spd!!!