oh man, where do we begin...
when it comes to any bmw, there are so many different models for each chassis.
these are the ones sold in North America only.......
1984-1985 318i - 1.8 L M10B18 I4, 101 hp (75 kW) - North America
1991 318iS - 1.8 L M42B18 I4, 134 hp (100 kW) - North America
1984-1991 325e - 2.7 L M20B27 I6, 121 hp (90 kW) - North America
1986-1991 325es - 2.7 L M20B27 I6, 121 hp (90 kW) - North America
1987-1991 325i/is - 2.5 L M20B25 I6, 168 hp (125 kW) - North America
1988-1991 325ix - 2.5 L M20B25 I6, 168 hp (125 kW) - North America
1988-1991 M3 - 2.3 L S14 I4, 192 hp (143 kW) - North America
and of course, all the different types sold in Europe....
1982-1987 316 - 1.6 L M98 I4, 90 hp (66 kW)
1982-1990 316 1.8 - 1.8 L M10B18 I4, 90 hp (66 kW)
1987-1993 316i - 1.6 L M40B16 I4, 102 hp (75 kW)
1982-1987 318i - 1.8 L M10B18 I4, 105 hp (77 kW)
1987-1993 318i - 1.8 L M40B18 I4, 115 hp (85 kW)
1989-1991 318is - 1.8 L M42B18 I4, 140 hp (103 kW)
1982-1985 320i - 2.0 L M20B20 I6, 125 hp (92 kW)
1985-1991 320i - 2.0 L M20B20 I6, 129 hp (95 kW)
1988-1990 320is - 2.0 L S14 I4, 192 hp (141 kW)
1982-1986 323i - 2.3 L M20B23 I6, 150 hp (110 kW)
1985-1991 325i - 2.5 L M20B25 I6, 170 hp (125 kW)
1986-1991 325iX - 2.5 L M20B25 I6, 170 hp (125 kW)
1986-1988 M3 - 2.3 L S14 I4, 200 hp (147 kW)
1989-1991 M3 Evo - 2.5 L S14 I4, 215 hp (158 kW)
1985-1991 324d - 2.4 L M21 I6, 86 hp (63 kW)
1987-1991 324td - 2.4 L M21 I6, 115 hp (85 kW)
the numbers on any bmw, ex. 318i , the "318" means its a 3 series, with a 1.8 liter motor. pretty simple.
the letters that come after the numbers (ex. 318i , the "i" simply means its a coupe) all mean something different.
"i" stands for coupe.
"is" stands for "sport."
"e" stands for "economy."
"es" stands for "economy sedan" i believe.
"ix" stands for all-wheel-drive.
"d" stands for "diesel."
"td" stands for "turbo-diesel."
"ic" stands for "convertible" even though they are not shown in the lists above.
and i cant exactly remember, but theres another code for the "touring" e30 which is the station wagon version.
the "M" in M3 stands for "Motorsport" which basically means that the car is equipped with a much more powerful motor and suspension package, as well as a more aggressive body kit and wider fenders, and also has 5 lug hubs, a brake upgrade, and various "Motorsport" parts unique to the interior.
They all have different values but if you can find an e30 M3 for a price that you like then go for it, otherwise you could find one you like, post up about it and we can help you judge if its worth it. I know older bmw's better than any other car out there i would say, probably because my dad has 3 of them. lol
also, this thread has some pictures of sweet e30's of all types, so scroll through every page of it, you wont get bored
http://www.floridagerman.com/forums/showthread.php?t=3346&highlight=obsessed