I've had (or have) the the same problems - And I don't have any uplifting comment I'm afraid.

There are several medium length bodies to get, but the only L-body i have found is made by Kamtec.co.uk and is a version of the VW Beetle.

But you can use Mini Coopers and the other M03/M05 bodies on your M04 (M or L version of course).

I have made this list of bodies that will fit on a M04. I haven't actually tried them all, since I can't get hold of them, but theese should fit.

• Tamiya, VW,
• Tamiya, Alfa Romeo MiTo, TAM51404
• Tamiya, Alfa Romeo Giulia Sprint,
• Tamiya, BMW Z3 M, TAM50848
• Tamiya, Mini Cooper S 2006, TAM51335
• Tamiya, Suzuki Swift Super 1600, TAM51236
• Tamiya, Porsche Boxster, TAM50754
• Tamiya, Fiat 500, TAM51363
• Tamiya, Fiat Abarth 500 Assetto Corse, TAM51387
• Tamiya, Mercedes SLK, TAM50756
• Tamiya, Eunos Roadster
• HPI, Datsun 240z, HPI7210
• HPI, Toyota Corolla Levin, HPI7213
• HPI, Honda Civic Mini, HPI7024, (Doesn't fit well, is a little narrow)
• HPI, Mazda Miata, HPI7205
• HPI, Datsun 510, HPI7209
• HPI, VW Golf,
• Kamtec, VW Beetle,
• Carson, Opel Speedster,
• Carson, Porsche 914,
• OPEL CORSA B from racersparadise_de shop on Ebay.de

Hope that helps somewhat...

Cheers,
Peter