This thread will never die...
Okay, let's try to revive it then with some actual relevant discussion.
Kaz recently mentioned they were trying to eventually add some Premium versions of
classic Standard cars already in GT5,
no new additions.
Whether this is going to be done in an update or via DLC is unknown, nor is it known when (or if at all....) this is going to take place.
Now we don't know in which context Kaz used the term classic car since it's a broad definition which could for example mean classic in the context of GT-games but I think the most logical use of the term would be to describe oldtimers, youngtimers, historically significant older cars or just plain old rubbish combined under the file classic cars.
Here's a list I copied, pasted and edited from the Master Car List (not sure it's complete or overcomplete for that matter) of Standard cars which could possibly be regarded as classic cars eligible for the full Premium nip and tuck.
AC Cars
Cobra 427 S/C '66
Alfa Romeo
Giulia Sprint GTA 1600 '65
Giulia Sprint Speciale '63
Spider 1600 Duetto '66
Alpine
A110 1600S '73
A310 1600VE '73
Audi
Quattro '82
Autobianchi
A112 Abarth '79
BMW
2002 Turbo '73
Buick
GNX '87
Special (SEMA Award 2003) '62
Caterham
Seven Fireblade '02
Chaparral
2D Race Car '67
2J Race Car '70
Chevrolet
Chevelle SS 454 '70
Corvette Convertible (C1) '54
Corvette Coupe (C2) '63
Corvette Stingray L46 350 (C3) '69
Corvette Z06 (C2) Race Car '63
Citroën
2CV Type A '54
Cizeta
V16T '94
DMC
DeLorean S2 '04
Dodge
Charger 440 R/T '70
Charger Super Bee 426 Hemi '71
Dome
Zero Concept '78
Ford
RS200 '84
RS200 Rally Car '85
Ginetta
G4 '64
Honda
1300 Coupe 9 S '70
Ballade Sports CR-X 1.5i '83
Beat '91
Beat Version F '92
Beat Version Z '93
City Turbo II '83
Civic 1500 3door 25i '83
Civic 1500 3door CX '79
Life Step Van '72
N360 '67
S500 '63
S600 '64
S800 '66
S800 RSC Race Car '68
Today G '85
Z Act '70
Isuzu
117 Coupe '68
Bellett 1600 GT-R '69
Piazza XE '81
Jaguar
E-Type Coupé '61
XJ220 '92
XJR-9 Le Mans '88
Jay Leno
Tank Car '03
Jensen
Interceptor MkIII '74
Lamborghini
Countach LP400 '74
Countach 25th Anniversary Edition '88
Lancia
Delta HF Integrale Rally Car '92
Delta S4 Rally Car '85
Stratos '73
Stratos Rally Car '77
Lotus
Carlton '90
Elan S1 '62
Esprit Turbo HC '87
Europa Special '71
Marcos
Mini Marcos GT '70
Mazda
110S (L10A) '67
110S (L10B) '68
Carol 360 Deluxe '62
Mercedes-Benz
190E 2.5-16 Evolution II '91
190E 2.5-16 Evolution II DTM '92
Sauber Mercedes C9 Le Mans '89
Mercury
Cougar XR-7 '67
Mini
Cooper 1.3i '98
Mitsubishi
Galant 2.0 DOHC Turbo VR-4 '89
Galant GTO MR '70
HSR-II Concept '89
Lancer 1600 GSR '74
Lancer 1600 GSR Rally Car '74
Lancer EX 1800 GSR IC Turbo '83
Mirage 1400GLX '78
Pajero Rally Raid Car '85
Starion 4WD Rally Car '84
Nissan
240RS Rally Car '85
240ZG (HS30) '71
Be-1 '87
Bluebird 1600 Deluxe (510) '69
Bluebird Hardtop 1800SSS (910) '79
Bluebird Rally Car (510) '69
Fairlady 2000 (SR311) '68
Fairlady 240ZG (HS30) '71
Fairlady Z 280Z-L 2seater (S130) '78
Fairlady Z 300ZX (Z31) '83
PAO '89
R89C '89
R92CP '92
Silvia (CSP311) '65
Silvia 240RS (S110) '83
Skyline 1500 Deluxe (S50D-1) '63
Skyline 2000GT-B (S54A) '67
Skyline 2000GT-R (KPGC110) '73
Skyline Hard Top 2000 Turbo RS (R30) '83
Skyline Hard Top 2000 RS-X Turbo C (R30) '84
Skyline Hard Top 2000GT-R (KPGC10) '70
Skyline Sport Coupe (BLRA-3) '62
Peugeot
205 Turbo 16 '85
205 Turbo 16 Rally Car '85
205 Turbo 16 Evolution 2 Rally Car '86
905 Le Mans '92
Plymouth
Cuda 440 Six Pack '71
Superbird '70
Pontiac
Tempest Le Mans GTO '64
Renault
5 Turbo '80
5 Maxi Turbo Rally Car '85
RUF
BTR '86
CTR "Yellowbird" '87
Shelby
GT350R '65
Subaru
360 '58
Toyota
7 Race Car '70
2000GT '67
Celica 1600GT (TA22) '70
Celica 2000 GT-Four (ST165) '86
Celica 2000 GT-R (ST162) '86
Celica XX 2800GT '81
Corolla Levin GT-Apex (AE86) '83
Minolta 88C-V '89
MR2 1600 G '86
MR2 1600 G-Limited Super Charger '86
Sports 800 '65
Sprinter Trueno GT-Apex (AE86) '83
Triumph
Spitfire 1500 '74
TVR
Griffith 500 '94
V8S '91
Volkswagen
Beetle 1100 Standard (Type-11) '49
Golf I GTI '76
Karmann Ghia Coupe (Type-1) '68
Volvo
240 GLT Estate '88
Which ones could be the most likely candidates? Try not just to think which ones you would pick yourself but which would really add something to the existing Premium line up 'objectively'.
Not sure how many Premiums could be added eventually, maybe 10, 15, 20 or just 5?
(I've added cars like the Caterham and Jay Leno Tank Car as well due to them being 'unique', although both ofcourse strictly speaking aren't classics)