Yes — but with caution. Since NFS MW is an offline, single-player game, using a trainer won’t get you banned (there’s no anti-cheat). However:
For advanced users, you can download a .CT file for Cheat Engine. This gives you granular control (e.g., "Freeze Timer for #15 on Blacklist") but requires more technical know-how. nfs mw mega trainer
The term "Mega" is not an exaggeration. A standard trainer gives you infinite nitrous. The Mega Trainer gives you the ability to drive a bus at 400 mph while the police fly into orbit. Below are the core features: Yes — but with caution