You said that he likes cars, one gift could be a keyring with the emblem of the make of car that he has - I have a sterling silver keyfob with VOLVO, the jeweller where I bought it had a number of different emblems, they just had to stick the correct one on for me. If you are feeling wealthy you can get them in gold instead of sterling! Perhaps there is something that he would particularly like to have for his car, some accessory.
Silk boxers would make a great gift - for you to share! You buy them for him and you get the benefit 
If he drinks beer at home you could get him a tankard.
A fun present could be a 'trophy' engraved with a message.
There is always the great standby, a sweater or shirt in his favourite colour.
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From over the pond....