An interesting bit of background reading (to be taken at face value) before rushing out and buying the cheapest filter! Apparently, the filter is common to all 4 cylinder Hondas from 1985 - 2007 (not confirmed) so sourcing one shouldn't be a problem. Some reported equivalents are as follows:
Crosland oil filter number 672
This filter is currently (2009) being supplied by Lotus.
www.Japspareparts.co.uk (duff link) ADS72101
K&N HP-1004 with 25mm hex key for very easy removal.
PURFLUX LS489A = 86 71 002 038 available from Renault dealers. (Quality AND cheap!)
Purflux LS 489 A
Mobil (Mobil 1) M1-104
Purolator PureOne PL14459
Castrol MaxPro Plus CMP3593A
MANN (german company): part # W811/80
additional information following research by Barry Dal Herbert (Sept 2020)
..... please note, you are advised to check all information for yourself, but this seems right!
Here are yet more possible oil filters for Elaners not in Oz or NZ. NOTE THE CAUTION IN THE NEXT LINE!
M100 oil filter equivalents gleaned from the Internet (frequently eBay listings, so NOT nessecelery correct!)
Lotus Elan-M100 Isuzu 1588cc 4XE1 engine
Said to fit: Mitsubishi 3000GT & Starion Turbo & Lotus Elan M100:
Clean Filters DO327
K&N Filters HP-1004
Mann W 811/80***
Mobil 1 M1-104
Ryco Syntec Z79AST
Sakura Oil Filter C1032
Wesfil Oil Filter WZ79
Height: 3.41 in (87 mm)
Outside Diameter: 3.14 in (80 mm)
Thread Inside Diameter: M20 x 1.5-6H
PSI Relief Valve: 11-17
Anti Drain Back Valve: Yes
Bypass Valve: Yes
Weight: 0.6 lb (0.3 kg)