OK, I am sure this has been covered, but I haven't been able to find it with a search.

Will any 18x8 or 18x8.5 wheel with 5x114.3 lug fit my car if the offset is close to 45mm? Will a 40mm fit? what about a 35 or a 33? Does the website have to say it is specific for my 6sp TL or if all the numbers match will I know it will fit?

 

The offset isn't necessarily the problem for the 6spd TL's, it's the clearance of the spokes. The 18" accessory wheels are 8.5" wide with a 35mm offset from what I've read, so you can use the numbers as baseline. The key is the design of the wheel face. Sometimes the spokes curve out and allow for a lot of clearance even with a smaller offset, but it's hard to know exactly what will fit without having someone tried it before. To be safe, I would try to stick with a higher offset 40+ and you should be fine on most 18" wheels that are 8.5" wide or less.