Thanks custom PC...

Here in Germany it cost about 30€ plus shipping(Price I'm not willing to pay)...and I just lost the muffler, manifold is still there... If it is not a good idea at all..I'll may have a friend make a muffler for me (he has a lathe shop) or buy a ASP muffler instead =(...
In my plane (Black horse su-31 with engine at 225°), I have the problem that I have to use an exhaust deflector, and they don't last there...the silicone deflectors are after a couple of flights just not there anymore, and there are 2 reasons: High exhaust temperature...the silicone deflectors break just where the muffler sting ends....or because there is not enough space to attach the deflector...

With this car muffler I won't hae the problem of the deflector because the sting is already deflected